[QE-users] Regarding Relaxing atomic positions with version 6.8

[Kondaiah Samudrala]

Dear Paolo,

This is happening for the past two months for every input structure with
new intel compilers(2020). If I use internal lapack and blas, then the same
input is running without any errors. But the computational time is very
high while using internal lapack and blas.
If need I can share the inputs with you personally for the test run(PS:
this work is going to publication). I am very confident about my input
structure but somehow diagonalization process is having some issues (I am
not a developer but frequent use. If I am wrong consider my apologies).
Kindly help me in this regard

with Regards
Konda

Dr. Samudrala Appalakondaiah
Postdoctoral Researcher
Department of Physics,
University of Seoul, Seoul 02504
South Korea
Phone no : +821028514541
Google Scholar ID:
https://scholar.google.co.in/citations?user=d8_gVLwJ&hl=en
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[QE-users] Regarding Relaxing atomic positions with version 6.8

[Kondaiah Samudrala]

Dear Minkyu Park,

Yes, I have tried with "cg", still having the same problem. But I will try
with other suggestion. Still, why does it happens for the latest
versions. The same input is running with 6.4 version or older.

with regards
Konda

University of Seoul, Seoul,
South Korea
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[QE-users] Regarding Relaxing atomic positions with version 6.8

[Kondaiah Samudrala]

Dear all,
I am a regular user of Quantum espresso and Recently, I am facing problems
with NSCF and relaxation calculations for standard structures. Below I am
showing you the error and my input
 (Especially, this situation isobserving with version 6.7 and 6.8 onwards)
 WARNING: integrated charge=   304.00358018, expected=   304.

 total energy  =-612.80361003 Ry
 estimated scf accuracy<   0.02578315 Ry

 iteration #  6 ecut=90.00 Ry beta= 0.30
 Davidson diagonalization with overlap

 %%
 Error in routine  cdiaghg (205):
  problems computing cholesky
 %%

&control
calculation = 'relax'
restart_mode='from_scratch',
prefix='silicon',
etot_conv_thr = 5.0D-7
forc_conv_thr = 5.0D-3
tstress = .true.
tprnfor = .true.
pseudo_dir = '/home/konda/Work/PWSCF/Psuedo/lda',
outdir='./tmp'
 /
&system
ibrav=  0,
nat=  76, ntyp= 1,
ecutwfc =90
occupations='smearing'
smearing='gaussian'
degauss=0.000734986
 /
 &electrons
   conv_thr =  1.0d-10
mixing_beta = 0.3
 /
&ions
/
ATOMIC_SPECIES
Si 28.0855 14_Si.upf
CELL_PARAMETERS (Angstrom)
16.708967320 0.0 0.0
 8.35448366014.470390170 0.0
 0.0 0.020.0
ATOMIC_POSITIONS (Angstrom)
Si 0.00 0.00 8.450871
Si10.55303214.216524 8.892564
Si 3.517677 1.523199 8.450871
Si 5.716226 1.269332 8.892564
Si 7.035355 3.046398 8.450871
Si 9.233903 2.792531 8.892564
Si10.553032 4.569597 8.450871
Si12.751580 4.315730 8.892564
Si14.070709 6.092796 8.450871
Si16.269258 5.838929 8.892564
Si17.588387 7.615995 8.450871
Si19.786935 7.362128 8.892564
Si21.106064 9.139194 8.450871
Si 6.595645 8.885327 8.892564
Si 7.91477410.662393 8.450871
Si10.11332210.408526 8.892564
Si11.43245112.185592 8.450871
Si13.63100011.931725 8.892564
Si14.95012913.708791 8.450871
Si17.14867713.454924 8.892564
Si10.113322 0.761599 8.450871
Si12.311871 0.507733 8.892564
Si13.631000 2.284798 8.450871
Si15.829548 2.030932 8.892564
Si17.148677 3.807997 8.450871
Si 2.638258 3.554131 8.892564
Si 3.957387 5.331196 8.450871
...
---
K_POINTS automatic
 8 8 1 0 0 0

Kindly suggest to me a possible solution. Thanks in advance

With Regads,
Konda

Dr. Samudrala Appalakondaiah
Postdoctoral Researcher
Department of Physics,
University of Seoul, Seoul 02504
South Korea
Phone no : +821028514541
Google Scholar ID:
https://scholar.google.co.in/citations?user=d8_gVLwJ&hl=en
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[QE-users] Compiling QE6.8 with Intel MPI and MKL

[Kondaiah Samudrala]

Dear all,

I am a regular user of Quantum Espresso.  Recently (from QE6.6version and
later), I am facing the below Installation error
--
mpiifort -O2 -assume byterecl -g -traceback -nomodule -fpp -D__MPI
-D__SCALAPACK  -I/home1/konda/Softwares/q-e-qe-6.8//external/devxlib/src
-I/home1/konda/Softwares/q-e-qe-6.8//include
-I/home1/konda/Softwares/q-e-qe-6.8//FoX/finclude   -c fft_scalar.FFTW3.f90
mpiifort -O2 -assume byterecl -g -traceback -nomodule -fpp -D__MPI
-D__SCALAPACK  -I/home1/konda/Softwares/q-e-qe-6.8//external/devxlib/src
-I/home1/konda/Softwares/q-e-qe-6.8//include
-I/home1/konda/Softwares/q-e-qe-6.8//FoX/finclude   -c fft_scalar.SX6.f90
mpiifort -O2 -assume byterecl -g -traceback -nomodule -fpp -D__MPI
-D__SCALAPACK  -I/home1/konda/Softwares/q-e-qe-6.8//external/devxlib/src
-I/home1/konda/Softwares/q-e-qe-6.8//include
-I/home1/konda/Softwares/q-e-qe-6.8//FoX/finclude   -c fft_scalar.cuFFT.f90
mpiifort -O2 -assume byterecl -g -traceback -nomodule -fpp -D__MPI
-D__SCALAPACK  -I/home1/konda/Softwares/q-e-qe-6.8//external/devxlib/src
-I/home1/konda/Softwares/q-e-qe-6.8//include
-I/home1/konda/Softwares/q-e-qe-6.8//FoX/finclude   -c fft_scalar.f90
fft_scalar.f90(37): #error:  No fft_scalar backend selected!

make[1]: *** [fft_scalar.o] Error 1
--
I have tried with both internal and intel FFTW3 versions.

 I am using Intel 2020 MPI and MKL compilers

My configure script:
./configure MPIF90=mpiifort CC=icc FC=ifort F77=ifort F90=ifort
BLAS_LIBS="${MKLROOT}/lib/intel64/libmkl_blas95_ilp64.a
${MKLROOT}/lib/intel64/libmkl_lapack95_ilp64.a -L${MKLROOT}/lib/intel64
-lmkl_intel_ilp64 -lmkl_intel_thread -lmkl_core -liomp5 -lpthread -lm -ldl"
LAPACK_LIBS="${MKLROOT}/lib/intel64/libmkl_blas95_ilp64.a
${MKLROOT}/lib/intel64/libmkl_lapack95_ilp64.a -L${MKLROOT}/lib/intel64
-lmkl_intel_ilp64 -lmkl_intel_thread -lmkl_core -liomp5 -lpthread -lm -ldl"
SCALAPACK_LIBS="${MKLROOT}/lib/intel64/libmkl_blas95_ilp64.a
${MKLROOT}/lib/intel64/libmkl_lapack95_ilp64.a -L${MKLROOT}/lib/intel64
-lmkl_scalapack_ilp64 -lmkl_intel_ilp64 -lmkl_intel_thread -lmkl_core
-lmkl_blacs_intelmpi_ilp64 -liomp5 -lpthread -lm -ldl"
FFT_LIBS="-L/home1/konda/Softwares/fftw-3.3.9/Build/lib -lfftw3"
--enable-qopenmp --with-scalapack=intel

Kindly suggest to me any missing parts in my installation process.

PS : If I am using internal Lapack, BLAS and FFTW compilers, then the
installation is successful but efficiency (especially time-consuming) is
less than Intel-based compilation

With Regards
S. Appalakondaiah


Dr. Samudrala Appalakondaiah
Postdoctoral Researcher
Department of Physics,
University of Seoul, Seoul 02504
South Korea
Phone no : +821028514541
Google Scholar ID:
https://scholar.google.co.in/citations?user=d8_gVLwJ&hl=en
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[Pw_forum] Regarding the description of tot_charge

[Kondaiah Samudrala]

Dear all,

I am bit confused with the "tot_charge" option between the documentation
and recent publication on MoS2 (doi:*10.1103/PhysRevB.94.024501*) . To my
understanding from input description and output of pwscf, I observed that
the tot_charge = +x leads to hole dope (electron missing from number of
electrons) and -x describes the electron dope (electron added to number of
electrons). To contrary this, recent publications reported as vice versa
(please find the work @ doi:*10.1103/PhysRevB.94.024501*).

This made me confuse and looking for exact meaning of tot_charge!!! I am
also keen to know the necessary of  supercell for this calculations.

Looking forward to hear a positive reply. Thanks in advance

with regards
S. Appalakondaiah
Postdoctoral scholar
SAINT, Sungkyunkwan University
South Korea
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[Pw_forum] Local density of states in momentum space with pwscf

[Kondaiah Samudrala]

Dear all,

I would like to know the output format units (x,y and f(x,y)) of iflag=2
and output format=7 in pp.x for plot_num=3.

 e.g output
 x   y
f(x,y)=LDOS
  0.E+00  0.E+00  0.74307971E-02
  0.E+00  0.13381399E+00  0.66185893E-02
  0.E+00  0.26762798E+00  0.58173600E-02
  0.E+00  0.40144197E+00  0.50624197E-02
  0.E+00  0.53525595E+00  0.43694517E-02
  0.E+00  0.66906994E+00  0.37497794E-02
  0.E+00  0.80288393E+00  0.32265849E-02


Indeed, I would like to plot Local density of states in momentum space (Kx
and Ky) at the Fermi level. can any one suggest me regarding the plotting
process !!!

Thanks in advance

with regards
S. Applakondaiah
postdoctoral scholar,
SAINT, SKKU, South Korea
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[Pw_forum] Installation error in EPW with QE-6.0-Beta version

[Kondaiah Samudrala]

Dear all,

I found below error for installation of epw (make epw ) in QE-6.0-beta
version. can any one suggest me the way to install

/mpif90 ../wannier_prog.F90  constants.o io.o utility.o parameters.o
hamiltonian.o overlap.o kmesh.o disentangle.o wannierise.o plot.o
transport.o /home/saint/Softwares/6.0/lapack-3.2/lapack.a
/home/saint/Softwares/6.0/BLAS/blas.a  -o ../../wannier90.x
parameters.o: file not recognized: File truncated
make[4]: *** [../../wannier90.x] Error 1
make[4]: Leaving directory
`/home/saint/Softwares/6.0/wannier90-2.0.1/src/obj'
make[3]: *** [wannier] Error 2
make[3]: Leaving directory `/home/saint/Softwares/6.0/wannier90-2.0.1'
make[2]: *** [w90] Error 1
make[2]: Leaving directory `/home/saint/Softwares/6.0/install'
make[1]: *** [w90] Error 1
make[1]: Leaving directory `/home/saint/Softwares/6.0'
make: *** [wannier] Error 2

PS: Also, some details/clarification on "band_plot" tool in epw update.

with best regards
S. Appalakondaiah
Postdoctoral scholar
SAINT, SKKU
South Korea
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[Pw_forum] Projection sites for convergence for my wannier initial and final states

[Kondaiah Samudrala]

Dear all,

I would like to enhance my convergence for my wannier initial and final
states. See the below for my ips and outputs. can any any one suggest me
for my inputs !!!

Thanks in advance

With regards
S. Appalakondaiah
Postdoctoral scholar
SAINT, SKKU

 Initial Wannier projections

 (   0.0   0.0   0.5) :  l =   2 mr =   1
 (   0.0   0.0   0.5) :  l =   2 mr =   2
 (   0.0   0.0   0.5) :  l =   2 mr =   3
 (   0.0   0.0   0.5) :  l =   2 mr =   4
 (   0.0   0.0   0.5) :  l =   2 mr =   5
 (   0.3   0.7   0.56936) :  l =   1 mr =   1
 (   0.3   0.7   0.56936) :  l =   1 mr =   2
 (   0.3   0.7   0.56936) :  l =   1 mr =   3
 (   0.3   0.7   0.43064) :  l =   1 mr =   1
 (   0.3   0.7   0.43064) :  l =   1 mr =   2
 (   0.3   0.7   0.43064) :  l =   1 mr =   3
 Wannier Function centers (cartesian, alat) and spreads (ang):

 (  -0.02096  -0.00223  -3.48836) :   1.75314
 (  -0.00664  -0.3   3.48837) :   1.84613
 (   0.00623   0.2   3.48837) :   1.84100
 (   0.13001  -0.00049  -3.48837) :   1.17645
 (  -0.10795   0.00272  -3.48836) :   1.15939
 (   0.14972   0.52279  -2.93224) :   1.37997
 (   0.42706   0.50949  -2.93714) :   1.39164
 (   0.27779   0.44727  -3.01302) :   1.92879
 (   0.15175   0.45475   2.93410) :   1.38915
 (   0.42621   0.47244   2.93870) :   1.40062
 (   0.27659   0.55403   3.00959) :   1.89966

Wannier input
begin projections
 Nb:d
 Se:p
end projections
num_wann  11
iprint   2
dis_win_min -1000.000
dis_win_max  1000.000
dis_froz_min -1000.000
dis_froz_max  -900.000
num_iter 300
 guiding_centres =
true





 bands_plot =
.true.





 begin
kpoint_path





 G 0.00 0.00 0.00 M 0.50 0.00
0.00





 M 0.50 0.00 0.00 K 0.33 0.33
0.00





 K 0.33 0.33 0.00 G 0.00 0.00
0.00





 end
kpoint_path





 bands_plot_format = gnuplot
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[Pw_forum] electron-phonon coupling with spin orbit coupling

[Kondaiah Samudrala]

Hi Anjali ,

Yes Of course. we can with gaussian smearing. I am not sure with FD, MP or
other smearing.

S. Appalakondaiah
Postdoctoral scholar
SAINT
SKKU
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[Pw_forum] Regarding Degaussq in lambda.in

[Kondaiah Samudrala]

 Dear all,

I was puzzled to fix the degaussq value (in Thz, which is not same used in
phonon) in *lambda.in * for calculating superconducting
temperature. If possible please provide me some path for determine this
parameter.

with best regards
S. Appalakondaiah
Postdoctoral Scholar,
SKKU, South Korea
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[Pw_forum] Regarding "elph.gamma.1" in Electron phonon calculations using PWSCF-5.3.0

[Kondaiah Samudrala]

Dear Ayria,

Thank you for the response..

"elph.#iq.#irr.xml contains the contribution to the electron phonon
coefficients at the q vector #iq of the representation #irr. These files
are written by elphel and contain the quantities g_qΜ (k, i, j)

Yes.. I am agree with you. But these are placed in elph_dir folder
(which are called now as elph.inp_lambda.1 to no of q points).
 On the other side, we will get elph.gamma.1, elph.gamma.2 and up to
elph.gamma.10 after the plotband.x calculations
(since el_ph_nsigma = 10 for my calculation. So, elph.gamma.XX should
relate to different smear values?? If so, How to we plot it??)

Here I am worrying and want to know about the description of these.

Also, I too searching about the expert explanation on EL-PH
calculations using PWSCF. Precisely,

1)  what is the el_ph_sigma ?? is it different from degauss of
electronic calculations??

2)  how to we choose degauss in lambda.x calculations?? (manual
specified different from phonon calculations)

3)  how to calculate phonon line widths from our calculations ??

These are basic things repeatedly asking in the forum and not having
specific documentation.

Hope some expert will discuss about these..

with best regards
S. Appalakondaiah
Research scholar
SAINT, SKKU
South korea
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[Pw_forum] Regarding "elph.gamma.1" in Electron phonon calculations

[Kondaiah Samudrala]

Dear all,

Can any one give the description/meaning of elph.gamma.1, elph.gamma.2-10
and also post processing after the completion of EL-PH calculations using
5.3.0 version???

With best regards
S. Appalakondaiah
Research Scholar
SAINT, SKKU
South Korea
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[Pw_forum] Regarding Smearing, Temprature effects and kohn Anomaly

[Kondaiah Samudrala]

Dear all,

I am just confusing with smearing effects to consider the Kohn anomaly.
>From several papers I observed Smearing factor play important role in Kohn
anomaly (or precisely say "effect on soft phonons" with smearing values).

>From my understanding, smearing factor contribute the electronic
temperature and it works very well in the usage of FD smearing..

So, Shall I use FD smearing for electronic part and gaussian smearing for
lambda.x calculations ??? ( From manual I got only mp and gauss only
implemented)

Or please give me suggestion/path for calculate Tc values in the case of
 materials which are having kohn anomaly

with best regards
S. Appalakondaiah
Research Scholar,
SAINT, SKKU
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[Pw_forum] Regarding degaussq in lambda.f90

[Kondaiah Samudrala]

Dear all,

Shall anyone suggest me the degaussq (in Thz) parameter in lambda.f90.
Specifically, how can we choose from our elph.out file??. I just simply
change with different values and found surprising Tc values. See the Below
values for two sets

For degauss 3618.82763 (summed over all degauss in elph.out and converted
the same from Ry to THz)

lambdaomega_log  T_c
   1.2271436.309  2.611
   0.8409336.309  1.228
   0.6787836.309  0.633
   0.6001536.309  0.382
   0.5960236.309  0.370
   0.6548836.309  0.552
   0.7323936.309  0.822
   0.8020936.309  1.081
   0.8562936.309  1.286
   0.8946836.309  1.432

For degauss 0.12 (which is given in examples file)
lambdaomega_log  T_c
   1.22714   148.755 10.697
   0.84093   153.319  5.186
   0.67878   159.776  2.784
   0.60015   162.623  1.711
   0.59602   159.329  1.624
   0.65488   153.195  2.330
   0.73239   148.374  3.361
   0.80209   145.126  4.321
   0.85629   142.853  5.061
   0.89468   141.194  5.569

Hoping positive reply .. Thanks in advance

with best regards
S. Appalakondaiah
Research Scholar
SAINT, SKKU
South Korea
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[Pw_forum] Regarding electron phonon calculations

[Kondaiah Samudrala]

Dear all,

I am calculating the Tc value of monolayer TMDS using electron-phonon
dispersions as given in example03.

Indeed, I found all my phonon frequencies are positive (except  first low
acoustic mode at gamma point, which is -4 cm-1). I also observed that my
elph.inp_lambda.1 is as below

   0.00  0.00  0.0010 9
 -0.147906E-08  0.382782E-08  0.382782E-08  0.140575E-05  0.140575E-05
0.411996E-05
  0.454432E-05  0.454432E-05  0.718661E-05

So, Shall I considered the first value (i.e.  -0.147906E-08) as zero for
lambda.x calculations or need to more refine my parameters for structural
optimizations??? below I am giving my details

For structural optimizations :
etot_conv_thr = 1.0D-10
forc_conv_thr = 1.0D-8
degauss=0.05,
smearing='gauss',
occupations='smearing',
conv_thr =  1.0d-12
Kpoints : 32 32 1
In this set up,  i found that the output stress is around 0.04.

For electron-phonon calculations
KPOINTS are 64 64 1 (in the case la2F=.true.)
KPOINTS are 32 32 1 (in normal SCF)
etot_conv_thr = 1.0D-10
forc_conv_thr = 1.0D-8
 tr2_ph=1.0d-16,
 electron_phonon='interpolated',
 el_ph_sigma=0.005,
 el_ph_nsigma=10,
 trans=.true.,
 ldisp=.true.
nq1=8, nq2=8, nq3=1

Hope a positive reply and thanks in advance

with best regards
S. Appalakondaiah
Researcher
SAINT, SKKU
South Korea
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[Pw_forum] lambda.x crshers with error (unit = 4, file = 'elph_dir/elph.inp_lambda.1)

[Kondaiah Samudrala]

Dear all,

I'm trying to do electron phonon calculation on monolayer transition
Metal chalcogens
When I try to calculate Tc using lambda.x (version PWSCF-5.3) i get this error:

At line 116 of file lambda.f90 (unit = 4, file = 'elph_dir/elph.inp_lambda.1')
Fortran runtime error: Bad value during floating point read

and empty file fort.4 shows up in my working folder.


12  0.12  0! emax (something more than highest phonon mode in THz),
degauss, smearing method
 10  ! Number of q-points for which EPC is calculated,
 0.00  0.00  0.00   1.00  !
 0.072823  0.126134  0.00   6.00  !
 0.145647  0.252267  0.00   6.00  !
 0.218470  0.378401  0.00   6.00  !
 -0.291293 -0.504535  0.00   3.00  !
 0.218470  0.126134  0.00   6.00  !
 0.291293  0.252267  0.00   12.00  !
 0.364117  0.378401  0.00   12.00  !
 0.436940  0.252267  0.00   6.00   !
 0.509763  0.378401  0.00   6.00   !
elph_dir/elph.inp_lambda.1 ! elph output file names,
elph_dir/elph.inp_lambda.2 ! in the same order as the q-points before
elph_dir/elph.inp_lambda.3
elph_dir/elph.inp_lambda.4
elph_dir/elph.inp_lambda.5
elph_dir/elph.inp_lambda.6
elph_dir/elph.inp_lambda.7
elph_dir/elph.inp_lambda.8
elph_dir/elph.inp_lambda.9
elph_dir/elph.inp_lambda.10
0.10 ! \mu the Coloumb coefficient in the modified
 ! Allen-Dynes formula for T_c (via \omega_log)

Any thing missing in my input ??? (PS: All my phonon frequencies are
positive) Suggest me something and thanks in advance

with best regards
S. Appalakondaiah
Postdoctoral scholar
HINT, SKKU,
South Korea
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[Pw_forum] Regarding symmetry of 2D materials with substitution

[Kondaiah Samudrala]

Dear Giovanni,

Thank you for quick response..
Precisely, In am loosing  the symmetry of hexagonal structure after
substitution of  metal atom (in higher kevel concentrations 10 to 50 %) to
pristine graphene. Shall I go for calculations with that structures

with best regards
S. Appalakondaiah
Researcher
SAINT
South Korea
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[Pw_forum] Regarding symmetry of 2D materials with substitution

[Kondaiah Samudrala]

Dear all,

Primary, I am struggling to make  direct substitute of a transition metal
to  graphene 2D mono layer (in different concentration levels with 4X4X1
super cell). Precisely, except from single atom substitution, all the other
output file changes their symmetry from hexagonal structure.

Here, I am confusing that the above effect is mainly from substitution or
any other  ??? (My supercell calculations with out substitution were
successful with hexagonal symmetries)

or

Shall I go for calculations with non-hexagonal structures of 2D
materials+direct substitutions ??

Please help me in this regard. Thanks in advance

S. Applakondaiah
Researcher
SAINT
Korea
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[Pw_forum] Regarding adsorption of metal atoms in graphene

[Kondaiah Samudrala]

Dear all,

I am very new to doing calculations for adsorption of metal atoms with 2D
materials(For e.g. graphene with metal atoms).

If someone have any tutorials or specific path to prepare the ATOMIC
POSITIONS and IBRAV for the these type calculations in PWSCF,  please
suggest me.

Thanks in advance

with best regards
S. Appalakondaiah
Researcher
HINT, SKKU
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Re: [Pw_forum] the high symmetry line of BCT phonon dispersion band structures

[Kondaiah Samudrala]

Dear Prof. Ari Paavo Seitsonen

Thank you very much.. I will look on that

with regards
S. Appalakondaiah
PhD Student
University of Hyderabad


On Tue, Dec 16, 2014 at 1:22 AM, Kondaiah Samudrala  wrote:
>
> Dear all,
>
> I am still confused with notation of Ibrav=7 in pwscf. The IBRV=7
>  primitive cell vectors in pwscf are quite different from any other. See
> below for two cases of primitive vectors IBRAV=7
> *Case1*
> For. e.g. In pwscf primitive vectors of IBRV=7 are
>  crystal axes: (cart. coord. in units of a)
>a(1) = (   0.50  -0.50   c/a)
>a(2) = (   0.50   0.50   c/a )
>a(3) = (  -0.50  -0.50   c/a )
> *Case 2*
> On the other hand, generally people used as (from published papers)
>  crystal axes: (cart. coord. in units of a)
>a(1) = (  -0.50  0.50c/a)
>a(2) = (   0.50   -0.50   c/a )
>a(3) = (   0.50   0.50   -c/a ) .
>
> This variation leads to changes in reciprocal vectors and then IBZ path.
> From Wikipedia (
> http://www.sciencedirect.com/science/article/pii/S0927025610002697) and 
> *http://www.cryst.ehu.es/
> <http://www.cryst.ehu.es/> , *I obtained the IBZ path for *case 2.  But, *what
> about the IBZ path of *case 1 primitive cell vectors*??  Is both are same
> ??? But Xcrysden showing something else than regular Gamma, Z, Sigma, P and
> N points .
>
> I feel puzzled, would some one give some idea about this? any help will be 
> appreciated
>
> with regards
>
> S. Appalakondaiah
> PhD Student
> University of Hyderabad
>
>
>
>
>
>
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Re: [Pw_forum] the high symmetry line of BCT phonon dispersion band structures

[Kondaiah Samudrala]

Dear Sir,

I Completed the Phonon calculations with IBRAV=7 option...Its quite
difficult to reperform the calculations. Can you please provide the
IBZ path or source for obtain the IBZ???

with regards

S. Appalakondaiah

PhD student

University of Hyderabad



On Tue, Dec 16, 2014 at 1:22 AM, Kondaiah Samudrala  wrote:
>
> Dear all,
>
> I am still confused with notation of Ibrav=7 in pwscf. The IBRV=7
>  primitive cell vectors in pwscf are quite different from any other. See
> below for two cases of primitive vectors IBRAV=7
> *Case1*
> For. e.g. In pwscf primitive vectors of IBRV=7 are
>  crystal axes: (cart. coord. in units of a)
>a(1) = (   0.50  -0.50   c/a)
>a(2) = (   0.50   0.50   c/a )
>a(3) = (  -0.50  -0.50   c/a )
> *Case 2*
> On the other hand, generally people used as (from published papers)
>  crystal axes: (cart. coord. in units of a)
>a(1) = (  -0.50  0.50c/a)
>a(2) = (   0.50   -0.50   c/a )
>a(3) = (   0.50   0.50   -c/a ) .
>
> This variation leads to changes in reciprocal vectors and then IBZ path.
> From Wikipedia (
> http://www.sciencedirect.com/science/article/pii/S0927025610002697) and 
> *http://www.cryst.ehu.es/
> <http://www.cryst.ehu.es/> , *I obtained the IBZ path for *case 2.  But, *what
> about the IBZ path of *case 1 primitive cell vectors*??  Is both are same
> ??? But Xcrysden showing something else than regular Gamma, Z, Sigma, P and
> N points .
>
> I feel puzzled, would some one give some idea about this? any help will be 
> appreciated
>
> with regards
>
> S. Appalakondaiah
> PhD Student
> University of Hyderabad
>
>
>
>
>
>
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[Pw_forum] the high symmetry line of BCT phonon dispersion band structures

[Kondaiah Samudrala]

Dear all,

I am still confused with notation of Ibrav=7 in pwscf. The IBRV=7
 primitive cell vectors in pwscf are quite different from any other. See
below for two cases of primitive vectors IBRAV=7
*Case1*
For. e.g. In pwscf primitive vectors of IBRV=7 are
 crystal axes: (cart. coord. in units of a)
   a(1) = (   0.50  -0.50   c/a)
   a(2) = (   0.50   0.50   c/a )
   a(3) = (  -0.50  -0.50   c/a )
*Case 2*
On the other hand, generally people used as (from published papers)
 crystal axes: (cart. coord. in units of a)
   a(1) = (  -0.50  0.50c/a)
   a(2) = (   0.50   -0.50   c/a )
   a(3) = (   0.50   0.50   -c/a ) .

This variation leads to changes in reciprocal vectors and then IBZ path.
>From Wikipedia (
http://www.sciencedirect.com/science/article/pii/S0927025610002697)
and *http://www.cryst.ehu.es/
 , *I obtained the IBZ path for *case 2.  But, *what
about the IBZ path of *case 1 primitive cell vectors*??  Is both are same
??? But Xcrysden showing something else than regular Gamma, Z, Sigma, P and
N points .

I feel puzzled, would some one give some idea about this? any help
will be appreciated

with regards

S. Appalakondaiah
PhD Student
University of Hyderabad
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[Pw_forum] Regarding K-PATH for PWSCF reciprocal vectors

[Kondaiah Samudrala]

Dear all,
Presently I am doing phonon  calculations for body centered tetragonal
structure with c> a. As the people known that pwscf "ibrav basis vectors
and their reciprocal vectors"  are different for other structure formats
and it is quite uncomfortable  to plot the phonon dispersions using
standard format kpath selection in electronicstructure.org.
At instance, I want to know kpath selection of BCT structure with
reciprocal vectors of b1= (1. -1.  0.), b2=(0.  1.
 0.6021), b3=(-1.  0.  0.6021) in 2pi/a units.
"If possible please provide me the source to understand the kpath
selections like gamma-X-Y-Z "


Thanks in advance
with regards
S. Appalakondaiah
PhD student
University of Hyderabad
India
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Re: [Pw_forum] LO-TO splitting in complete phonon dispersion using PWSCF

[Kondaiah Samudrala]

Dear all,

I am looking to know the possibility of asr  rule for non zero q point
(along any other special point from GAMMA direction)  Is it
possible???. If no, How can PWscf phonon dispersion plots contains LO-TO
splitting in whole phonon dispersion relation!

Help me in this doubt... Thanks in advance


with regards
S. Appalakondaiah
PhD Student
University of Hyderabad
India.
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Re: [Pw_forum] LO-TO splitting in complete phonon dispersion using PWSCF

[Kondaiah Samudrala]

Dear Sir,

Thank you for the suggestion. Now, I found imaginary acoustic modes (around
-80 cm-1) at ambient conditions and the same closes to zero at high
pressures using with out using Born effective charges ( I changed T to F
and removed the charges )in .fc file. On the other side, All my frequencies
are positive from ambient to entire pressures using with born effective
charges.

It is bit surprising me. Am I miss some thing  If possible please
provide me the IBZ special points of BCT structure with Pwscf basis vectors
for c/a > 1

with regards
S. Appalakondaiah
PhD Scholar
University of Hyderabad
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Re: [Pw_forum] LO-TO splitting in complete phonon dispersion using PWSCF

[Kondaiah Samudrala]

Dear SIr,

Sorry for not provide the symmetry of the system. My system crystallizes in
Body centered tetragonal (ibrav=7); 3 atoms/cell with celldm(1)=   8.017350
and celldm(3)=   1.660948.

In detail, I found huge splitting of the LO and TO modes of IR modes at
ambient pressure (in the Gamma point level), where as the  gap was closed
under pressure. The same I want to check with complete dispersion as well
as try to compute the effect on other special points in IBZ.  Of course I
finished the phonon dispersion calculations with LO-TO splitting but I am
not able to zoom out  the LO-TO (or LA-TA) in other directions

Also, I want to know the details (or please refer any source or tutorial)
and difference of *"fleig"* and *"fldyn". *Surprisingly I was not able to
find any frequencies in fidyn out put file. My out put is as follows

Dynamical  Matrix in cartesian axes

 q = (0.01000   0.0   0.0 )

11
  0.04011368  0.0.  0.0.  0.8840
  0.  0.0.03267074  0.0.  0.
  0. -0.88400.  0.0.27929359  0.
12
  0.01491749  0.0.  0.0. -0.00016204
  0.  0.0.00747601  0.0.  0.


If possible please suggest me the high symmetry points of the BCT structure
for PWSCF with c/a> 1.

My Basis vectors are

 crystal axes: (cart. coord. in units of alat)
   a(1) = (   0.50  -0.50   0.830474 )
   a(2) = (   0.50   0.50   0.830474 )
   a(3) = (  -0.50  -0.50   0.830474 )


Thanks in advance

with regards
S. Appalakondaiah
PhD student
University of Hyderabad
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Re: [Pw_forum] LO-TO splitting in complete phonon dispersion using PWSCF

[Kondaiah Samudrala]

Dear Sir,
Sorry for the eps figure. Now I attached new figure with pdf extension
In the mean time, I am following the same definition for LO-TO splitting at
Gamma point level.  But, I am not clear about the below sentence far from
Gamma.


"An the end of the dynamical matrix file you have the frequencies and the atom
displacements (3 times number of atoms complex numbers). If the displacement
for every atom is parallel to the q-point, the mode is Longitudinal; if it
is orthogonal, the mode is Transverse. In every other case it is neither.
You can then associated the frequency with the label.".

I would like to know that is there any possibility to know more details far
from Gamma point. Here with I am adding the ip and ops of matdyn.x ( Here I
am using only one special point in the IBZ)

*Matdyn.in :*
&input
   asr='crystal',q_in_band_form=.true.
fleig='matdyn.eig', fldyn='AB22.dyn',flfrc='AB2444_with_ASR.fc',
flfrq='AB2_with_ASR.freq'
 /
 1
 0.5 0.5 0.5 2

*AB2.dyn* :
 Dynamical  Matrix in cartesian axes

 q = (0.5   0.5   0.5 )

11
  0.03952920  0.   -0.00374183  0.0.  0.
 -0.00374183  0.0.03952920  0.0.  0.
  0.  0.0.  0.0.29542189  0.
12
  0.02007831 -0.0009   -0.01131717  0.006725040.  0.
 -0.01131717  0.006725040.02007831 -0.00090.  0.
  0.  0.0.  0.   -0.03673002  0.00282937
13
 -0.04191744  0.00060.00162178 -0.000699500.  0.
  0.00162178 -0.00069950   -0.04191744  0.00060.  0.
  0.  0.0.  0.   -0.25545367 -0.00387305
21
  0.02007831  0.0009   -0.01131717 -0.006725040.  0.
 -0.01131717 -0.006725040.02007831  0.00090.  0.
  0.  0.0.  0.   -0.03673002 -0.00282937
22
  0.03952920  0.   -0.00374183  0.0.  0.
 -0.00374183  0.0.03952920  0.0.  0.
  0.  0.0.  0.0.29542189  0.
23
 -0.04191744 -0.00060.00162178  0.000699500.  0.
  0.00162178  0.00069950   -0.04191744 -0.00060.  0.
  0.  0.0.  0.   -0.25545367  0.00387305
31
 -0.04191744 -0.00060.00162178  0.000699500.  0.
  0.00162178  0.00069950   -0.04191744 -0.00060.  0.
  0.  0.0.  0.   -0.25545367  0.00387305
32
 -0.04191744  0.00060.00162178 -0.000699500.  0.
  0.00162178 -0.00069950   -0.04191744  0.00060.  0.
  0.  0.0.  0.   -0.25545367 -0.00387305
33
  0.10704556  0.   -0.00739632  0.0.  0.
 -0.00739632  0.0.10704556  0.0.  0.
  0.  0.0.  0.0.54383493  0.

*matdyn.modes:*

diagonalizing the dynamical matrix ...

 q =   0.5000  0.5000  0.5000
 **
 freq (1) =   1.318544 [THz] =  43.981900 [cm-1]
 ( -0.411001   0.032309-0.411001   0.032309 0.00   0.00   )
 ( -0.381067  -0.157332-0.381067  -0.157332 0.00   0.00   )
 ( -0.395193  -0.062378-0.395193  -0.062378 0.00   0.00   )
 freq (2) =   1.662161 [THz] =  55.443739 [cm-1]
 (  0.00   0.00 0.00   0.00 0.578232   0.001810   )
 (  0.00   0.00 0.00   0.00 0.578232  -0.001810   )
 (  0.00   0.00 0.00   0.00 0.575577   0.00   )
 freq (3) =   2.140009 [THz] =  71.383008 [cm-1]
 (  0.249628   0.355541-0.249628  -0.355541 0.00   0.00   )
 (  0.274220  -0.336937-0.274220   0.336937 0.00   0.00   )
 (  0.349855   0.012425-0.349855  -0.012425 0.00   0.00   )
 freq (4) =   2.763777 [THz] =  92.189664 [cm-1]
 ( -0.043052   0.489305 0.043052  -0.489305 0.00   0.00   )
 ( -0.032204  -0.490138 0.032204   0.490138 0.00   0.00   )
 ( -0.132110  -0.001463 0.132110   0.001463 0.00   0.00   )
 freq (5) =   4.043036 [THz] = 134.861157 [cm-1]
 ( -0.061283   0.494864-0.061283   0.494864 0.00   0.00   )
 ( -0.060611  -0.494947-0.060611  -0.494947 0.00   0.00   )
 (  0.052041   0.35 0.052041   0.35 0.00   0.00   )
 freq (6) =   5.972075 [THz] = 199.206984 [cm-1]
 ( -0.480641  -0.101587 

Re: [Pw_forum] LO-TO splitting in complete phonon dispersion using PWSCF

[Kondaiah Samudrala]

Dear Dr. Lorenzo Paulatto


Thank you for the conformation.. How can I distinguish the both
modes.. i.e whether LO or TO. Because, in the phonon dispersion plot,
I observed  that my GAMMA point having two numbers ( pls see the
values Gamma-X and M to Gamma directions...). Here with I am attaching
the plot.


Please suggest me sir


with regards

S. Appalakondaiah

PhD Schloar

University of Hyderabad


0-PD.eps
Description: PostScript document
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[Pw_forum] LO-TO splitting in complete phonon dispersion using PWSCF

[Kondaiah Samudrala]

Dear all,
I am curious about the possibility of phonon dispersion with LO-TO
splitting in pwscf. I am sure, there is tutorials for LO-TO at gamma point,
where as not for complete dispersion.

Since, My material is a wide band gap insulator and I found huge changes of
LO and TO modes under pressure (at Gamma point level). At present, I want
to check the same LO-TO nature in all special points of the IBZ

Hope, some utility or tutorial is available for the above issue...

I performed ph x calculations using below input
   prefix='XeF2',
   fildyn='XeF2.dyn',
   tr2_ph=1.0d-16,
   outdir='./tmp'
   ldisp=.true.,
   nq1=4, nq2=4, nq3=4

and I found .fc file as

11  0.00  0.00  0.4779672000
21  0.00  0.00 -0.4779672000
32  0.00  0.00  0.00
 T
  2.2192318  0.000  0.000
  0.000  2.2192318  0.000
  0.000  0.000  3.5742157
1
 -0.5300825  0.000  0.000
  0.000 -0.5300825  0.000
  0.000  0.000 -2.0015990
2
 -0.5300825  0.000  0.000
  0.000 -0.5300825  0.000
  0.000  0.000 -2.0015990
3
  1.0610398  0.000  0.000
  0.000  1.0610398  0.000
  0.000  0.000  4.0034960
   4   4   4
   1   1   1   1
   1   1   1   3.03920731974E-02
..


Thanks in advance

with regards
S. Appalakondaiah
PhD Student
University of Hyderabad
India.
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[Pw_forum] Regarding LA_TA modes

[Kondaiah Samudrala]

Respected Dr. Lorenzo Paulatto,

Thank you for Quick reply..May be it is basic and crude to ask like
this.can you please explain me the *"**displacement pattern of the
atoms"* in pwscf output.. I am not clear..Otherwise please give me
some path for understand the output..

Thanks in advance

with regards

S. Appalakondaiah

PhD Student

University of Hyderabad
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[Pw_forum] Regarding LA_TA modes

[Kondaiah Samudrala]

Dear all,

I'm wondering if anybody knows how to identified LA-TA modes along
high symmetry directions. I have 8 atoms system , which gives 24 modes
at Gamma point. On the other hand, at X-direction it shows 12
modes(each mode is degenerate). So how can I identified LA and TA
modes. I am sure that all transverse modes are degenerate.. That means
no LA mode along this direction Below, I copy the first 4 modes
along X-Direction

I am very happy to know the  Gruneisen parameter spectrum  along High
symmetry directions by QE. I haven't seen any example file or document
about above mentioned
quantities.

Hope Pssitive reply from experts

 q =   0.  0.5000  0.
 **
 omega( 1) =   1.598127 [THz] =  53.307789 [cm-1]
 (  0.00   0.00-0.066130   0.00-0.125554   0.00   )
 (  0.00   0.00 0.109756   0.00 0.075649   0.00   )
 (  0.00   0.00-0.068974   0.00-0.432281   0.00   )
 (  0.00   0.00 0.041559   0.00 0.717454   0.03   )
 (  0.00   0.00 0.078828   0.00 0.051986   0.00   )
 (  0.00   0.00-0.047495   0.00-0.086281   0.00   )
 (  0.00   0.00 0.180727   0.00 0.287614   0.01   )
 (  0.00   0.00-0.299951  -0.01-0.173293   0.00   )
 omega( 2) =   1.598127 [THz] =  53.307789 [cm-1]
 (  0.00   0.00 0.109756   0.00-0.075649   0.00   )
 (  0.00   0.00 0.066130   0.00-0.125554   0.00   )
 (  0.00   0.00-0.041559   0.00 0.717454   0.00   )
 (  0.00   0.00-0.068974   0.00 0.432281   0.02   )
 (  0.00   0.00 0.047495   0.00-0.086281   0.00   )
 (  0.00   0.00 0.078828   0.00-0.051986   0.00   )
 (  0.00   0.00-0.299951   0.00 0.173293   0.01   )
 (  0.00   0.00-0.180727  -0.01 0.287614   0.00   )
 omega( 3) =   2.327611 [THz] =  77.640735 [cm-1]
 (  0.100914   0.29 0.00   0.00 0.00   0.00   )
 ( -0.023825   0.00 0.00   0.00 0.00   0.00   )
 ( -0.174218  -0.02 0.00   0.00 0.00   0.00   )
 (  0.737912   0.000209 0.00   0.00 0.00   0.00   )
 ( -0.019375   0.00 0.00   0.00 0.00   0.00   )
 (  0.082062   0.23 0.00   0.00 0.00   0.00   )
 (  0.621104   0.000176 0.00   0.00 0.00   0.00   )
 ( -0.146640  -0.02 0.00   0.00 0.00   0.00   )
 omega( 4) =   2.327611 [THz] =  77.640735 [cm-1]
 (  0.023825   0.06 0.00   0.00 0.00   0.00   )
 (  0.100914  -0.01 0.00   0.00 0.00   0.00   )
 (  0.737912  -0.08 0.00   0.00 0.00   0.00   )
 (  0.174218   0.46 0.00   0.00 0.00   0.00   )
 (  0.082062  -0.01 0.00   0.00 0.00   0.00   )
 (  0.019375   0.05 0.00   0.00 0.00   0.00   )
 (  0.146640   0.38 0.00   0.00 0.00   0.00   )
 (  0.621104  -0.07 0.00   0.00 0.00   0.00   )


with Regards
S. Appalakondah
PhD student
University of Hyderabad
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[Pw_forum] Regarding LA-TA modes

[Kondaiah Samudrala]

Dear all,

I am very much interested in knowing  LA-TA modes and grunessian parameter
calculations using pwscf.

Is it possible to get non zero acoustic modes at Gamma point. Because, If I
am applying asr rule at gamma point, the acoustic modes are zero in my
case. How can we define LA-TA modes ???

Is degenerative modes (Out of First three modes)  are transverse modes???

How to do grunessinn parameter calculations for entire phonon spectrum  in
PWscf???

Hope positive reply..Thanks in advance

with regards
S. Appalakondaiah
PhD student
University of Hyderabad
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[Pw_forum] Fwd: fft-check warning: sum of imaginary terms 0 .1649464E-06 in q2r.x

[Kondaiah Samudrala]

Dear all,

I am calculating Phonon dispersion of AB2 type compound under pressure up
to 150 GPa. From 0 to 90 GPa i got nice phonon dispersions, where as I
found

*fft-check warning: sum of imaginary terms= .1649464E-06*

warning at 100 GPa and 110 GPa.

Even After seen the forums i put large conversion values such as
etot_conv_thr = 1.0D-8 ,
forc_conv_thr = 1.0D-5 ,
conv_thr = 1.D-10 ,
tr2_ph=1.0d-16,

I did the calculations with 120 Ry and 14X12X12 k-mesh, 4X4X4 and 6X6X6
q-mesh for phonon dispersions. My 0 to 90 GPa computed values are good in
agreement with experiments. Including this, I did not get ant imaginary
frequenciesin AB2.dyn files at 90 GPa and 100 GPa.  Here with I am
attaching My 90 GPa and 100 GPa phonon dispersions

Pls help me in this problem. Thanks in advance


with regards
S. Applakondaiah
Senior research fellow
University of Hyderabad
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[Pw_forum] Regarding Phonon dispersions

[Kondaiah Samudrala]

Dear Dr. Sanjeev ,
Here with I am attaching my i/p. I don't know the necessity of scf i/p for
LO-TO calculations at q!=0 cases. If possible, please explain me...

Can Any one Pls suggest me or Answer me regarding q!=0 LO-TO splitting in
Quantum espresso.

with regards
S. Applakondaiah

&control
calculation = 'scf'
restart_mode='from_scratch',
prefix='ZnGeP2',
tprnfor = .true.
pseudo_dir = '../pseudo',
outdir='./tmp/'
etot_conv_thr = 1.0E-6  ,
forc_conv_thr = 1.0D-5 ,
 /

 &system
  ibrav  = 7
 celldm(1)   = 10.3888344123,
 celldm(3)   = 1.971766212270,
 nat = 8
 ntyp= 3
 ecutwfc = 35
 ecutrho = 600

 /

 &electrons
 conv_thr= 1.0d-12
 /

 ATOMIC_SPECIES
  Zn65.39   Zn.pw91-n-van.UPF
  Ge72.61   Ge.pw91-n-van.UPF
  P 30.97   P.pw91-n-van.UPF

 ATOMIC_POSITIONS (crystal)
 Zn   0.0   0.0   0.0
 Zn   0.5   0.75000   0.25000
 Ge   1.0   0.5   0.5
 Ge   0.5   0.25000   0.75000
 P0.003266411   0.37500   0.871733589
 P0.496733589   0.128266411   0.12500
 P0.503266411   0.621733589   0.62500
 P0.996733589   0.87500   0.378266411

 K_POINTS (automatic)
  7 7 8  1 1 1
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[Pw_forum] Regarding Phonon dispersions

[Kondaiah Samudrala]

Dear all,

Can anyone perform Phonon dispersions with LO-TO splitting for body centerd
tetragonal structure with Quantum espresso??.

I am sure and did LO-TO spllitting calculations at q=0. But, I am really
worried about implementation of LO-TO splitting in Quantum espresso at q!=0
cases in semiconductors and insulators Whether it is working for all q
points or not

with regards
S. Applakondaiah
University of Hyderabad
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[Pw_forum] Regarding LO-TO phonon dispersions for semiconductors and insulators

[Kondaiah Samudrala]

Dear all,

I successfully completed the phonon dispersion calculations for  tetragonal
structure (insulator) by following example06.
Now, I want to add LO-TO splitting to plot the phonon dispersion. Can any
one please suggest me for necessary  flags added to ph.x, q2r.x and
matdyn.x inputs.

Here I am adding my ips ..Thanks in advance
*For phonons*
phonons at Full
 &inputph
   prefix='$NAME',
   fildyn='$NAME.dyn',
   tr2_ph=1.0d-16,
   epsil=.true.
   amass(1)=18.99840,
   amass(2)=24.305,
   outdir='./tmp'
   ldisp=.true.,
   nq1=4, nq2=4, nq3=4
 /
*q2r.x*
&input
   fildyn='$NAME.dyn', zasr='simple',flfrc='$NAME2444_with_ASR.fc'
*matdy.x*
 &input
amass(1)=18.998,amass(2)=24.305, asr='simple',
flfrc='$NAME444_with_ASR.fc', flfrq='$NAME_with_ASR.freq'

With regards
S. Applakondaiah
PhD student
University of Hyderabd
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[Pw_forum] Regarding units for phonon dispersion in Pwscf

[Kondaiah Samudrala]

Dear all,

I successfully completed the ph0non dispersion calculations for AB2 type
compound. Surprisingly, I found the units of ph0non frequencies are in eV
while plotting dispersion. Pls see the below

Reading9 bands at200 k-points
Range:0.  571.5027eV  Emin, Emax >

I also checked in the ph.out, where all the phonon frequencies are in
cm-1...

 omega(  1 -  1) = 19.0  [cm-1]   --> A_2u X_4' M_4'  I
 omega(  2 -  3) = 26.9  [cm-1]   --> E_u  X_5' M_5'  I
 omega(  4 -  5) =132.4  [cm-1]   --> E_g  X_5  M_5   R
 omega(  6 -  7) =195.6  [cm-1]   --> E_u  X_5' M_5'  I

Is it plotband.x shows error or something I missed in my i/p.. Help in this
problem

Thanks in advance

with regards
S. Appalakondaiah
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[Pw_forum] Regarding Kpoint and qpoint grids

[Kondaiah Samudrala]

Dear all,

I am performing phonon dispersion calculations for AB2 type Body centered
tertagonal structure with lattice parameters a= 4.315 and c =6.990. While
performing SCF calculations, I used 10 X10 X7 k grid and i got all forces
are <10-5 eV/atom. After that, I used 4X4X3 q grid for phonon dispersion,
my o/p says symmetry breaking, where as If i am using 4 X4 X 4 q-grid my
phonon dispersion shows imaginary frequencies at acoustic phonons.

Pls help me in choosing Kpoint and qpoint grids for any crystal
structures(except cubic).



with regards
S. Appalakondaiah
University of Hyderbad
Hyderbad
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[Pw_forum] Phonon dispersion with LO-TO splitting in teragonal system

[Kondaiah Samudrala]

-- Forwarded message --
From: Kondaiah Samudrala 
Date: Tue, Dec 17, 2013 at 6:49 PM
Subject: Phonon dispersion with LO-TO splitting
To: pw_forum-owner at pwscf.org, pw_forum at pwscf.org, pw_forum-request at 
pwscf.org



Dear all,

I am phonon dispersion for teragonal system to check insulator to metal
transition. At gamma point frequencies,  I did not get any imaginary
frequencies in asr.out file, where as in complete phonon dispersion I got
imaginary frequencies and sudden shifts in high symmetry directions. I am
bit confused and croos check my i/p. Below I attached the i/p and o/p of
calculations

AB2.asr.out :
 Reading Dynamical Matrix from file AB2.dynG
 ...Force constants read
 ...epsilon and Z* read
 A direction for q was not specified:TO-LO splitting will be absent

 Polarizability (A^3 units)
 multiply by 0.273227 for Clausius-Mossotti correction
21.4100690.000.00
 0.00   21.4100690.00
 0.000.00   18.627445

 IR activities are in (D/A)^2/amu units

# mode   [cm-1][THz]  IR
1  0.000.0.
2  0.000.0.
3  0.000.0.
4257.237.71162.1831
5257.237.71162.1831
6412.71   12.37270.
7412.71   12.37270.
8539.77   16.1819   24.4707
9620.07   18.58910.

 DYNMAT   : 0.00s CPU 0.03s WALL


   This run was terminated on:  22:47:55  16Dec2013

=--=
   JOB DONE.
=--=

AB2.ph.in

phonons at Full
 &inputph
   prefix='AB2',
   fildyn='AB2.dyn',
   tr2_ph=1.0d-16,
   outdir='./tmp'
   ldisp=.true.,
   nq1=4, nq2=4, nq3=4
 /


My lattice parameters are a= 3.4 and c=6.1 \AA . Pls correct me If I did
any wrong...

One more doubt is.. How to include LO-TO splitting in Complete phonon
dispersion I am doing Insulator to metal transition, and metal did not
contains LO-TO splitting. So, I  check LO-TO changes at transition pressure
and the same I want to compare with ambient pressure .

Looking for favorable reply and Thanks in advance...


with regards
S. Appalakondaiah
Research scholar
University of Hyderabad
Hyderabad
India
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[Pw_forum] Regarding Van der waals corrections for Xe

[Kondaiah Samudrala]

Dear all,
I have two doubts regarding Van der waals correction methods:

There is no C6 value for Xe. Whether I can use for "london=.true." option
for Xe base compounds???

Whether london=.true. for all functionals ( i mean, LDA, PW91, PBEsol) or
explicitly for PBE only

Thanks in advance

with regards
S. Appalakondaiah
Research scholar
University of Hyderabad
Hyderabad
India
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[Pw_forum] Regarding K-Grid in electron phonon calculations

[Kondaiah Samudrala]

Dear all,

Presently, I am studying electron phonon coupling for the metals, which are
crystallizes in orthorhombic and monoclinic structure. Earlier, i did
successful calculations for cubic materials with  32X32X32 kpoint and 4X4X4
q grids. Now, I am confuse with present orthorhombic and monoclinic
structure grids. If I am using equivalent q-grid , i got below error

 from lint : error #   203
 cannot remap grid on k-point list


 My optimized K-grids are 10X5X8 for VC-relax. How can i fix the q grids
for electron phonon coupling.. I mean equal (nXnXn) grids or non equivalent
grids???


Hope for positive reply. Thanks in advance



with regards
S. Appalkondaiah
Research schloar
ACRHEM
University of Hyderabad
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[Pw_forum] Fwd: Regarding Animations in vibrational spectrum

[Kondaiah Samudrala]

Dear all,

We successfully completed the gamma point frequencies of orthorhombic
structure using pw.x,  ph.x and dynamat.x. Now we want to analyze
vibrational property of each mode like bending, stretching or wagging etc..
How can we get these properties using PWscf or Xcryden.

Thanks in advance

with regards
S.Appalakondaiah
Research schloar,
University of Hyderabad
India
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[Pw_forum] Regarding Animations in vibrational spectrum

[Kondaiah Samudrala]

Dear all,

We successfully completed the gamma point frequencies of orthorhombic
structure using pw.x,  ph.x and dynamat.x. Now we want to analyze
vibrational property of each mode like bending, stretching or wagging etc..
How can we get these properties using PWscf or Xcryden.

Thanks in advance

with regards
S.Appalakondaiah
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[Pw_forum] Running QHA calculations for orthorhombic structure

[Kondaiah Samudrala]

Dear all,

I am working on base centered orthorhombic structure with space group 64. I
run complete phonon dispersion for this compound, but i want to calculate
thermodynamic quantities such as specific heat, thermal expansion for this
compound. Whether it is possible to calculate these things using QHA for
base centered orthorhombic structure in pwscf???


with regards
S.Appalakondaiah
Research scholar
HCU
Hyd-500046
India
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[Pw_forum] Regarding QHA calculations

[Kondaiah Samudrala]

Dear all,

As First,  Thank you to all helping me in previous questions. I have some
basic doubts in  extending QHA calculations.

1) Is QHA implementation with pwscf is up to primitive orthorhombic only???
Now i want to calculate QHA properties for body centered orthorhombic
structure.  Recently i have seen several literature for different crystal
structure. please suggest me in that point

2) I want to calculate lattice parameters, bulk modulus w.r.t Temperature ,
Thermal expansion coefficient and Grunessian parameter  using QHA. Is there
any tutorial or basic i/ps for those calculations???
  If possible please explain me for cubic structure.

Thanks in advance

with regards
S.Appalakondaiah
Research scholar
University of Hyderabad
India
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[Pw_forum] Regarding QHA

[Kondaiah Samudrala]

Thank you sir, i tried from 100K
 But my problem is still not solved.

  100.00  0.0088104354   NaN
10.2931041201
  NaN
  105.00  0.0091386637   NaN
10.4342538793   NaN
  110.00  0.0094711026   NaN
10.5594404965   NaN
  115.00  0.0098072828   NaN
10.6708830330   NaN
  120.00  0.0101467994   NaN
10.7704462241   NaN
  125.00  0.0104893018   NaN
10.8597023137   NaN
  130.00  0.0108344853   NaN
10.9399816499   NaN
  135.00  0.0111820840   NaN
11.0124140277   NaN
  140.00  0.0115318651   NaN
11.0779624771   NaN
  145.00  0.0118836238   NaN
11.1374509121   NaN
  150.00  0.0122371799   NaN
11.1915868004   NaN
  155.00  0.0125923738   NaN  11.2409797990
NaN
  160.00  0.0129490636   NaN
11.2861571157   NaN
  165.00  0.0133071235   NaN
11.3275762129   NaN
  170.00  0.0136664408   NaN
11.3656353467   NaN
  175.00  0.0140269147   NaN
11.4006823396   NaN
  180.00  0.0143884549   NaN
11.4330219083   NaN
  185.00  0.0147509798   NaN
11.4629218040   NaN
  190.00  0.0151144161   NaN
11.4906179758   NaN

Pls help me in this

with regards
S.Appalakondaiah
Research Scholar
HCU
INDIA
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[Pw_forum] Pw_forum Digest, Vol 61, Issue 49

[Kondaiah Samudrala]

Thank you sir, i tried from 100K
 But my problem is still not solved.

  100.00  0.0088104354   NaN
10.2931041201   NaN
  105.00  0.0091386637   NaN
10.4342538793   NaN
  110.00  0.0094711026   NaN
10.5594404965   NaN
  115.00  0.0098072828   NaN
10.6708830330   NaN
  120.00  0.0101467994   NaN
10.7704462241   NaN
  125.00  0.0104893018   NaN
10.8597023137   NaN
  130.00  0.0108344853   NaN
10.9399816499   NaN
  135.00  0.0111820840   NaN
11.0124140277   NaN
  140.00  0.0115318651   NaN
11.0779624771   NaN
  145.00  0.0118836238   NaN
11.1374509121   NaN
  150.00  0.0122371799   NaN
11.1915868004   NaN
  155.00  0.0125923738   NaN
11.2409797990   NaN
  160.00  0.0129490636   NaN
11.2861571157   NaN
  165.00  0.0133071235   NaN
11.3275762129   NaN
  170.00  0.0136664408   NaN
11.3656353467   NaN
  175.00  0.0140269147   NaN
11.4006823396   NaN
  180.00  0.0143884549   NaN
11.4330219083   NaN
  185.00  0.0147509798   NaN
11.4629218040   NaN
  190.00  0.0151144161   NaN
11.4906179758   NaN

Pls help me in this

with regards
S.Appalakondaiah
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[Pw_forum] Regarding QHA calculations

[Kondaiah Samudrala]

Dear all,

I completed successfully phonon dispersion calculations for cubic  (ibrav=
1) compound without any imaginary frequencies. When i am trying QHA
approximation .. i got below error

#   T E_internalF_vibration  Specific heat
(C_v)   Entropy

0.00   NaN   NaN
NaN   NaN
5.00  0.0049960582   NaN
0.0670241577   NaN
   10.00  0.0050013101   NaN
0.3147779147   NaN
   15.00  0.0050196360   NaN
0.8999194212   NaN
   20.00  0.0050613782   NaN
1.7727713167   NaN
   25.00  0.0051333709   NaN
2.7850724371   NaN
   30.00  0.0052378692   NaN
3.8091143892   NaN
   35.00  0.0053739475   NaN
4.7713131374   NaN
   40.00  0.0055390448   NaN
5.6388435196   NaN
   45.00  0.0057299757   NaN
6.4027181221   NaN
   50.00  0.0059434901   NaN
7.0663660164   NaN
   55.00  0.0061765495   NaN
7.6388978030   NaN

  Is theer any error in my calculations???

with regards
S.Appalakondaiah
UOH
Hyd
India
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[Pw_forum] regarding phonon dispersion

[Kondaiah Samudrala]

Dear all,

I am running phonon dispersion for YSn3, which is crystallizes in cubic
structure. While running the programme i dont have any imaginary
frequencies in my o/p file (ph.out). But using plotband.x tool  for
plotting dispersion,  my final plot got negative axis exactly starting from
the value of Fermi energy. Below i am sending the plotband.x details

Reading   12 bands at101 k-points
Range:0.  133.5007eV  Emin, Emax > 0 140
high-symmetry point:  0. 0. 0.   x coordinate   0.
high-symmetry point:  0.5000 0. 0.   x coordinate   0.5000
high-symmetry point:  0.5000 0.5000 0.   x coordinate   1.
high-symmetry point:  0. 0. 0.   x coordinate   1.7071
high-symmetry point:  0.5000 0.5000 0.5000   x coordinate   2.5731
high-symmetry point:  0.5000-0.5000 0.5000   x coordinate   3.5731
high-symmetry point:  0. 0. 0.5000   x coordinate   4.2802
output file (xmgr) > YSn3.xmgr
bands in xmgr format written to file
YSn3.xmgr

output file (ps) > YSn3.ps
Efermi > 13.2559
deltaE, reference E (for tics) 30, 13.2559
bands in PostScript format written to file YSn3.ps  .

Is there any error in my calculation or any bug in plotband.x. Because the
same o/p YSn3.xmgr from this plotband.x shows nicely with xmgrce shows.

please help me  in this. Thanks in advance

S.Appalakondaiah
Research scholar
University of Hyderabad
Hyderabad
India
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[Pw_forum] requesting for thermodynamical properties

[Kondaiah Samudrala]

Dear All,

I am new to pwscf. I want to calculate thermodynamical properties using
PWSCF. will you please any one.

Thanks in advance


with regards
S.Appalakondaiah
research scholar
University of Hyderabad
India
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[Pw_forum] Regarding Vdw interactions

[Kondaiah Samudrala]

Dear all,

I have confusion on implementation of grimme (london = .true.) in DFT. Is
it valid only for ground state or at high pressures also

Please give clarification for me to do High pressure structral transitions
using grimme correction to PBE is how much valid?


I expect favorable reply

Thanks in advance

with regards
S.Appalakondaiah
Research scholar
University of Hyderabad
Hyderabad
India
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[Pw_forum] Requesting for structural details

[Kondaiah Samudrala]

Dear All,

I am working on layered type material which crystallizes in rhombohedral
structure with space group 166 ( ibrav =5). In the i/p file for VC-Relax, i
used the lattice parameters and angle as  celldm(1)=7.4870 and
celldm(4)=0.586005.

In the first step of the of the o/p file shows the basis vectors as
0.454970 -0.262677 0.850884
0.00 0.525354 0.850884
-0.4504970 -0.262677 0.850884

After completing the VC-Relax i got the basis vectors as


CELL-PARAMETERS ( alat=7.4870)
0.441119855 -0.254680667 0.78874941
0.   0.509361335 0.78874941
-0.441119855 -0.254680667 0.78874941

  with this o/p values, how can i calculate lattice vector and angle for my
material ( For orthorhombic and tetragonal structures i calculated lattice
parametrs successfully but i am not able to do this structure ).


i am requesting your favorable reply.

with regards
S.Appalakondaiah
PhD Scholar
University of Hyderabad
Hyderabad
India
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[Pw_forum] Regarding raman spectra

[Kondaiah Samudrala]

   Dear all,
   I get the result of cross section of Raman and IR. The results are:

#  mode   [cm-1] [THz]  IR   Raman depol
1  0.00   -0.00010. 0.0.7298
2  0.000.0. 0.0.4596
3  0.000.0. 0.0.3769
4 72.482.17280.2093 0.0.7221
5181.805.45030.  1725.78320.7500
6216.896.50230.  2083.45000.7500
7363.65   10.90210. 91729.50390.2795
8396.95   11.90010.104976.37800.7500
9420.27   12.59920. 0.0.6389
   10425.05   12.74270.  1248.54190.7500
   11451.38   13.53210.329620.46540.3306
   12460.15   13.79490.1942 0.0.3225

   The result of raman data are very well compared with the experimental
result. But I am not able to plot Raman spectrum with this o/p using
XMGRACE.

   Please give me suggetion for plot raman spectra. Here with i attached
direct plot of my trail with xmgrace (2 and 5th colums) .

   What is the meaning of cross section in this calculation?

   Please provide norm conserving pseudopotential for phosphorus using GGA
(PBE or PW91) XC-functional ( Using LDA-CAPZ is already in website).

   Finally, for structural properties semiemperical correction of Vdw
interactions plays very importent role. But, Is there any  influence of
semiemperical  correction  to Vdw interaction on vibrational properties
.

  I appreciate to all your instructions.

  with regards
  S.Appalakondaiah
  Research Schloar
  University of hyderabad
  Hyderabad
  India
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[Pw_forum] Regarding structural optimization

[kondaiah samudrala]

Dear Sir,

(1) Here i am running Black phosphorous, which is layered compound
crystallizes in orthorhombic structure and reported that having huge van
der waals forces. Generally systems having van der waals forces shows
huge volume change( either 10-12% underestimate in LDA or 5-6% overestimate
in GGA)  with experimental volume in DFT calculations. In my case, CASTEP
and VASP i got similar variation in volume. But in PwSCF, i got 2%
volume change with experimental volume. Here i used 50Ry cutoff and
10X10X10 K-mesh is used for my calculations. For energy minimum i used
up to 10e-8 . Where as in "vc-relax" calculations i got 10% volume
change with experimental volume.

 please give your suggestions for my problem. If it is need i will send
my b/a, c/a and a calculation input  and output files to your mail.

(2) What is the difference in structural optimization between normal
process( optimizain c/a, b/a and a with energy) and "vc-relax"?



Thanks in advance.


with regards
S.Appalakondaiah
Research scholar
University of Hyderabad
Hyderabad
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[Pw_forum] Pw_forum Digest, Vol 51, Issue 44

[kondaiah samudrala]

Dear Sir,

  Thank you for your reply. I am sorry for not sending complete details.
Here i am running Black phosphorous, which is layered compound and reported
that havng huge van der waals forces. Genarally systems having van der waals
forces shows volume change( either 10-12% underestimate in LDA or 5-6%
overestimate in GGA)  with experimental volume in DFT calculations. In my
case,CASTEP and VASP i got similar variation in volume. But in PwSCF, i got
2% volume change with experimental volume. Here i used 50Ry cutoff and
10X10X10 K-mesh is used for my calculations. For energy minimum i used upto
10e-8 .Where as in "vc-relax" calculations i got 10% volume change with
experimental volume.

 please give your suggestions for my problem. If it is need i will send my
b/a, c/a and a calculation input  and output files to your mail.

with regards
S.Appalakondaiah
Research scholar
University of Hyderabad
Hyderabad
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[Pw_forum] regarding structural optimization

[kondaiah samudrala]

Dear all,

   I am doing test calculations for orthorhombic  layered compounds having
van der waals forces.  i calculated the volume by varying c/a, b/a and a
with energy and taken the minimum values of c/a, b/a and a. But my volume
change is surprisingly 2% with experimental ( even van der waals forces
having). I tried with the "vc-relax" for same system i found 12% volume
change with experimental.I tried with psedopotentials also and the results
are same.

I am very thankful any to solve this problem.

Thanks in advance

S.Appalakondaiah
Research Scholar
University of hyderabad
Hyderabad
India
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[Pw_forum] regarding kpoint

[kondaiah samudrala]

Dear sir
I have a simple question regarding kpoints.will you please explain how to
choose kpoints in Band structure calculations( after scf calculation)  for
different crystal structures.i know the crystal symmetry directions but i am
not getting proper band structure.

with regards
S.Appalkondaiah
Research Schlor
University of Hyderabad
Hyderabad
India
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