[Pw_forum] Electron affinity calculation using Quantum Espresso
Dear Researchers Could you please tell me how can I calculate electron affinity using quantum espresso pwscf package? In a reference, I found the definition to be: "However, a different definition holds for finite systems. In this case, the electron affinity is defined as EA=E(N)-E(N+1) where E(N) and E(N+1) are the total ground-state energies in the neutral (N) and single charged (N+1) configurations" ---http://arxiv.org/pdf/0801.1961.pdf If I want to calculate affinity for MoS2 monolayer, according to this reference, I need to calculate ground state energy for neutral system and then charged system and then find out the difference between the two. Is this sufficient? Please let me know. Thanks in advance. Sincerely yours Kanak Datta Dept. of EEE, BUET ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum
Re: [Pw_forum] Electron affinity calculation using Quantum Espresso
Dear Kanak, > > "However, a different definition holds for finite systems. In this case, the > electron affinity is defined as > EA=E(N)-E(N+1) where E(N) and E(N+1) are the total ground-state energies in > the neutral (N) and single charged (N+1) > configurations" > this is the so-called Delta-scf method, applied to the calculation of electron affinities (similarly one can compute IP=E(N-1)-E(N) ) Concerning the EA of MoS2, there are two problems (1) delta-scf methods work only for finite systems (when using standard DFT functionals such as LDA or GGA's), while MoS2 is extended. (2) even for finite systems, EA's may be difficult to compute since approximate DFT functionals may not be able to bind the extra electron to compute E(N+1) (this ia actually the most common situation, especially when dealing with a very flexible basis set as plane waves). This is actually not specific to MoS2, but a general problem. In these cases, a more effective way is to compute the N+1 eigenvalue when 0.5 electrons have been added to the system (Slater 1/2 type of approach), approximating by taylor expansion the E(N)-E(N+1) difference without requiring to bind a full electron (just half of it) Feasible alternatives to compute HOMO and LUMO bands (IP and EA) for extended systems such as MoS2 are based on GW calculations... Take care Andrea > > If I want to calculate affinity for MoS2 monolayer, according to this > reference, I need to calculate ground state energy > for neutral system and then charged system and then find out the difference > between the two. Is this sufficient? Please > let me know. > > Thanks in advance. > > Sincerely yours > Kanak Datta > Dept. of EEE, BUET > > -- Andrea Ferretti, PhD S3 Center, Istituto Nanoscienze, CNR via Campi 213/A, 41125, Modena, Italy Tel: +39 059 2055322; Skype: andrea_ferretti URL: http://www.nano.cnr.it ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum
[Pw_forum] Program received signal SIGSEGV: Segmentation fault - invalid memory reference.
Dear allI am facing some strange problem about all versions from 5.0 to 5.3.0
of Quantum Espresso. I serached archievs at pwscf forum but could not solve
this problem.
I am using Fedora GNU Fortran (GCC) 4.8.3 20140911 (Red Hat 4.8.3-7).This error
also appears for parallel and serial executions.
The error is
iteration # 1 ecut= 30.00 Ry beta=0.30
Davidson diagonalization with overlap
ethr = 1.00E-02, avg # of iterations = 3.3
Program received signal SIGSEGV: Segmentation fault - invalid memory reference.
Backtrace for this error:
#0 0x411ECDD3
#1 0x411ED498
#2 0x43FF
#3 0x410C39A9
#4 0x4101A844
#5 0x4101A964
#6 0x41018163
#7 0x4101D7CA
#8 0x4101D283
#9 0x4101D7CA
#10 0x4101D283
#11 0x410BDCBB
#12 0x823ED22 in __fft_scalar_MOD_cfft3d at fft_scalar.f90:1280
#13 0x823CA91 in fwfft_x_ at fft_interfaces.f90:222
#14 0x81E5CE3 in interpolate_ at interpolate.f90:75
#15 0x815372B in sum_band_ at sum_band.f90:142
#16 0x8088D55 in electrons_scf_ at electrons.f90:486
#17 0x808E586 in electrons_ at electrons.f90:132
#18 0x804D804 in run_pwscf_ at run_pwscf.f90:90
#19 0x804D537 in pwscf at pwscf.f90:30
#20 0x48ED8962
I perform calculations for different lattice constants from 10.1170 to 11.7170
with difference of 0.1 ( i.e 10.2170 10.3170 10.4170 10.5170 10.6170
10.7170...and so on). Above error appear for 10.5170, 106170, 10.8170, and
upto 11.2170 ) the rest values executes without any error. The input file is
&CONTROL
calculation='scf',
prefix ='VSe'
tstress=.t.,tprnfor=.t.,
outdir='/home/zafar/Pwscf/scratch',
pseudo_dir='/home/zafar/pslibrary.1.0.0/pbe/PSEUDOPOTENTIALS'
verbosity='high'
/
&SYSTEM
ibrav= 2 ,
celldm(1)= 10.5170,
nat= 2, ntyp= 2,
ecutwfc=30.0,
ecutrho = 200.0
/
&ELECTRONS
mixing_mode = 'plain'
diagonalization='david'
mixing_beta = 0.3
conv_thr = 1.0d-8
/
ATOMIC_SPECIES
Zn 65.409 Zn.pbe-nc.UPF
Se 78.960 Se.pbe-n-nc.UPF
ATOMIC_POSITIONS crystal
Zn 0.000 0.000 0.000
Se 0.250 0.250 0.250
K_POINTS {automatic}
9 9 9 0 0 0
Hope that some one will help me..
Muhammad Zafar
PhD Scholar
Department of Physics
The Islamia University of Bahawalpur,Pakistan___
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Re: [Pw_forum] E-field: please any response!
Dear Jaret
Sometimes it happens that we simply do not have any useful answer...
You are mixing an impressive amount of "non standard" DFT features
like electric field, full DFT+U method, in a junction between strongly
correlated, open-shell systems. If something goes wrong it is *very
difficult* to say what! So try first "brute force":
mixing_beta=0.02,
electron_maxstep=1000
If you still do not reach convergence, then start simplifying your
system toward plain DFT. I do not know why you are using the sawtooth
potential, but you could also flick through the documentation of all
the assume_isolated='esm' cases. One of them might be useful to you,
and the calculation are quite stable, at least in my experience.
HTH
Giuseppe
Quoting Jaret Qi :
> Hello QE users,I am trying to apply saw-like electric field on a
> structure (input is given below), but it reached 500 step without
> converging, I do not know if something wrong with the input file,
> please take a look on the input:
> -part of
> the output: total energy = -3007.64456350 Ry
> Harris-Foulkes estimate = -3007.64456538 Ry
> estimated scf accuracy < 0.2171 Ry
>
> total magnetization = 0.39 Bohr mag/cell
> absolute magnetization = 3.46 Bohr mag/cell
>
> End of self-consistent calculation
>
> convergence NOT achieved after 500 iterations: stopping
> -
> Input: &control
> calculation = 'relax'
> restart_mode = 'from_scratch'
> pseudo_dir = './'
> outdir = './'
> nstep = 100 ,
> tefield = .true.
> dipfield = .true.
> /
> &system
> ibrav=0
> celldm(1)=7.540006694
> nat=40
> ntyp=7
> ecutwfc = 30 ,
> ecutrho=300
> occupations='smearing'
> degauss=0.02
> nspin=2
> starting_magnetization(2) = 1
> lda_plus_u = .true.
> Hubbard_U(2)= 2
> Hubbard_J0(2)=0.7
> edir = 3
> eamp = 0.00
> emaxpos = 0.7
> eopreg = 0.1
> /
> &electrons
> mixing_beta=0.3,
> electron_maxstep=500
> /
> &IONS
> /
>
> ATOMIC_SPECIES
> ---
> ATOMIC_POSITIONS (alat)
> La 0.001181668 0.001181668 6.050060401
> Mn 0.469738707 0.469738707 6.565742621
> O 0.469473688 0.469473688 6.085964317
> O 0.468843692 0.000348383 6.538606525
> O 0.000348383 0.468843692 6.538606525
> Sr 0.001039864 0.001039864 7.064792061
> Mn 0.469676094 0.469676094 7.557901982
> O 0.469624727 0.469624727 7.056571078
> O 0.468925802 0.000293611 7.575881614
> O 0.000293611 0.468925802 7.575881614
> La 0.000993325 0.000993325 8.089910079
> Mn 0.469504247 0.469504247 8.593701257
> O 0.469318550 0.469318550 8.039436909
> O 0.469234084 0.000344639 8.527412698
> O 0.000344639 0.469234084 8.527412698
> Pb -0.014392827 -0.014392827 0.254329743 1 1 0
> Ti 0.449335594 0.449335594 0.744524878 1 1 0
> O 0.445630194 0.445630194 0.292667664 1 1 0
> O 0.446866894 -0.020789811 0.782939868 1 1 0
> O -0.020789811 0.446866894 0.782939868 1 1 0
> Pb -0.016727738 -0.016727738 1.262175978
> Ti 0.450604754 0.450604754 1.820354388
> O 0.447848259 0.447848259 1.358571068
> O 0.447194479 -0.020103191 1.926302938
> O -0.020103191 0.447194479 1.926302938
> Pb -0.006882381 -0.006882381 2.371864847
> O 0.446926722 0.446926722 2.551971810
> O 0.468151164 -0.002813857 3.241466866
> O -0.002813857 0.468151164 3.241466866
> Pb -0.004895228 -0.004895228 3.694395477
> Ti 0.469851616 0.469851616 4.313940138
> O 0.470070311 0.470070311 3.861981065
> O 0.469479771 0.000630908 4.426237872
> O 0.000630908 0.469479771 4.426237872
> Pb 0.002684401 0.002684401 4.871067455
> Ti 0.470100084 0.470100084 5.489734431
> O 0.469191796 0.469191796 5.033815628
> O 0.469294913 0.000554244 5.600299218
> O 0.000554244 0.469294913 5.600299218
> Zr 0.464031631 0.464031631 3.060505444
> K_POINTS {automatic}
> 6 6 1 0 0 0
>
> CELL_PARAMETERS alat
> 0.937980317 -0.09219 -0.000131497
> -0.09219 0.937980317 -0.000131497
> -0.001221078 -0.001221078 15.641997242
>
>
> --thank youJaret, QiASU
--
- Article premier - Les hommes naissent et demeurent
libres et égaux en droits. Les distinctions sociales
ne peuvent être fondées que sur l'utilité commune
- Article 2 - Le but de toute association politique
est la conservation des droits naturels et
imprescri
Re: [Pw_forum] E-field: please any response!
By the way: in the provided input, eamp=0 implies "no electric field"
Paolo
On Sun, Jan 31, 2016 at 7:25 PM, Giuseppe Mattioli <
giuseppe.matti...@ism.cnr.it> wrote:
>
> Dear Jaret
> Sometimes it happens that we simply do not have any useful answer...
> You are mixing an impressive amount of "non standard" DFT features
> like electric field, full DFT+U method, in a junction between strongly
> correlated, open-shell systems. If something goes wrong it is *very
> difficult* to say what! So try first "brute force":
>
> mixing_beta=0.02,
> electron_maxstep=1000
>
> If you still do not reach convergence, then start simplifying your
> system toward plain DFT. I do not know why you are using the sawtooth
> potential, but you could also flick through the documentation of all
> the assume_isolated='esm' cases. One of them might be useful to you,
> and the calculation are quite stable, at least in my experience.
> HTH
> Giuseppe
>
> Quoting Jaret Qi :
>
> > Hello QE users,I am trying to apply saw-like electric field on a
> > structure (input is given below), but it reached 500 step without
> > converging, I do not know if something wrong with the input file,
> > please take a look on the input:
> >
> -part of
> > the output: total energy = -3007.64456350 Ry
> > Harris-Foulkes estimate = -3007.64456538 Ry
> > estimated scf accuracy< 0.2171 Ry
> >
> > total magnetization = 0.39 Bohr mag/cell
> > absolute magnetization= 3.46 Bohr mag/cell
> >
> > End of self-consistent calculation
> >
> > convergence NOT achieved after 500 iterations: stopping
> > -
> > Input: &control
> > calculation = 'relax'
> > restart_mode = 'from_scratch'
> > pseudo_dir = './'
> > outdir = './'
> > nstep = 100 ,
> > tefield = .true.
> > dipfield = .true.
> > /
> > &system
> > ibrav=0
> > celldm(1)=7.540006694
> > nat=40
> > ntyp=7
> > ecutwfc = 30 ,
> > ecutrho=300
> > occupations='smearing'
> > degauss=0.02
> > nspin=2
> > starting_magnetization(2) = 1
> > lda_plus_u = .true.
> > Hubbard_U(2)= 2
> > Hubbard_J0(2)=0.7
> > edir = 3
> > eamp = 0.00
> > emaxpos = 0.7
> > eopreg = 0.1
> > /
> > &electrons
> > mixing_beta=0.3,
> > electron_maxstep=500
> > /
> > &IONS
> > /
> >
> > ATOMIC_SPECIES
> > ---
> > ATOMIC_POSITIONS (alat)
> > La 0.001181668 0.001181668 6.050060401
> > Mn 0.469738707 0.469738707 6.565742621
> > O0.469473688 0.469473688 6.085964317
> > O0.468843692 0.000348383 6.538606525
> > O0.000348383 0.468843692 6.538606525
> > Sr 0.001039864 0.001039864 7.064792061
> > Mn 0.469676094 0.469676094 7.557901982
> > O0.469624727 0.469624727 7.056571078
> > O0.468925802 0.000293611 7.575881614
> > O0.000293611 0.468925802 7.575881614
> > La 0.000993325 0.000993325 8.089910079
> > Mn 0.469504247 0.469504247 8.593701257
> > O0.469318550 0.469318550 8.039436909
> > O0.469234084 0.000344639 8.527412698
> > O0.000344639 0.469234084 8.527412698
> > Pb -0.014392827 -0.014392827 0.2543297431 1 0
> > Ti 0.449335594 0.449335594 0.7445248781 1 0
> > O0.445630194 0.445630194 0.2926676641 1 0
> > O0.446866894 -0.020789811 0.7829398681 1 0
> > O -0.020789811 0.446866894 0.7829398681 1 0
> > Pb -0.016727738 -0.016727738 1.262175978
> > Ti 0.450604754 0.450604754 1.820354388
> > O0.447848259 0.447848259 1.358571068
> > O0.447194479 -0.020103191 1.926302938
> > O -0.020103191 0.447194479 1.926302938
> > Pb -0.006882381 -0.006882381 2.371864847
> > O0.446926722 0.446926722 2.551971810
> > O0.468151164 -0.002813857 3.241466866
> > O -0.002813857 0.468151164 3.241466866
> > Pb -0.004895228 -0.004895228 3.694395477
> > Ti 0.469851616 0.469851616 4.313940138
> > O0.470070311 0.470070311 3.861981065
> > O0.469479771 0.000630908 4.426237872
> > O0.000630908 0.469479771 4.426237872
> > Pb 0.002684401 0.002684401 4.871067455
> > Ti 0.470100084 0.470100084 5.489734431
> > O0.469191796 0.469191796 5.033815628
> > O0.469294913 0.000554244 5.600299218
> > O0.000554244 0.469294913 5.600299218
> > Zr 0.464031631 0.464031631 3.060505444
> > K_POINTS {automatic}
> > 6 6 1 0 0 0
> >
> > CELL_PARAMETERS alat
> >0.937980317 -0.09219 -0.000131497
> > -0.09219 0.937980317 -0.000131497
> > -0.001221078 -0.001221078 15.6419
[Pw_forum] PWgui installation Problem
Dear All
I am trying to run Pwgui-5.3.0 in fedora 23(64 bit) OS. my system spec are
Intel Core duo with 4Gb ram. when i hit
./pwgui
with PWgui-5.3.0 folder i am getting the following error meassage
I checked installed packages and i already have itk itcl and tk tcl in the
following path
/usr/lib64/tcl8.6/itk4.0.1
/usr/lib64/tcl8.6/itk4.0.1
/usr/lib64/tcl8.6/
/usr/lib64/tk8.6
can anyone help in shorting out the problem
[pearl@localhost PWgui-5.3.0]$ ./pwgui
==
This is PWgui version: 5.3.0
--
PWgui: using the system default "tclsh" interpreter
PWGUI : /home/pearl/Downloads/PWgui-5.3.0
GUIB engine : /home/pearl/Downloads/PWgui-5.3.0/lib/Guib-0.5.1
can't find package Itk
while executing
"package require Itk "
(file "/home/pearl/Downloads/PWgui-5.3.0/lib/Guib-0.5.1/init.tcl" line
11)
invoked from within
"source /home/pearl/Downloads/PWgui-5.3.0/lib/Guib-0.5.1/init.tcl"
("package ifneeded Guib 0.5.1" script)
invoked from within
"package require Guib 0.5"
(file "/home/pearl/Downloads/PWgui-5.3.0/init.tcl" line 5)
invoked from within
"source [file join $env(PWGUI) init.tcl]"
(file "/home/pearl/Downloads/PWgui-5.3.0/pwgui.tcl" line 62)
[pearl@localhost PWgui-5.3.0]$
similar problem have been reported previously
https://www.mail-archive.com/pw_forum@pwscf.org/msg18098.html
Thank you
*-*
*Muthu.V Sri Paramakalyani CollegeIndia
-*
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