Re: [Pw_forum] Error in davcio running head.x
Actually reducing the cutoffs was the solution to my previous problem, but it was an error in davcio in pw4gww. The same solution doesn't work here with head.x. Do you suggest that there is a problem related to the disk space? Thank you 2014-10-22 7:29 GMT+02:00 Paolo Giannozzi : > On Tue, 2014-10-21 at 18:22 +0200, Valentina Cantatore wrote: > > > > The program stops with the error: > > "Error in routine davcio (25): error while writing from file > > "*/./out/_ph0/*.prd38". > > > > I had a similar problem with a calculation on a molecular system and > > you suggested me to reduce the cutoffs. It worked in that case. > > I seriously doubt that it worked because you reduced the cutoff. > The I/O should write no mater what the cutoff is, as long as there > is enough disk space and file size does not exceed the allowed > maximum length > > Paolo > > > Now I have significantly reduce them but I have the same problem. I > > use Quantum Espresso 5.1 and I work with 64 CPUs. > > > > > > I attach the input files for the pwx calculation and for the head one. > > > > > > Any help will be really appreciated. > > > > > > Thank you very much > > > > > > Valentina Cantatore > > PostDoc@Università del Piemonte Orientale, Alessandria > > ___ > > Pw_forum mailing list > > Pw_forum@pwscf.org > > http://pwscf.org/mailman/listinfo/pw_forum > > -- > Paolo Giannozzi, Dept. Chemistry&Physics&Environment, > Univ. Udine, via delle Scienze 208, 33100 Udine, Italy > Phone +39-0432-558216, fax +39-0432-558222 > > ___ > Pw_forum mailing list > Pw_forum@pwscf.org > http://pwscf.org/mailman/listinfo/pw_forum ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum
Re: [Pw_forum] Error in davcio running head.x
On Tue, 2014-10-21 at 18:22 +0200, Valentina Cantatore wrote: > The program stops with the error: > "Error in routine davcio (25): error while writing from file > "*/./out/_ph0/*.prd38". > > I had a similar problem with a calculation on a molecular system and > you suggested me to reduce the cutoffs. It worked in that case. I seriously doubt that it worked because you reduced the cutoff. The I/O should write no mater what the cutoff is, as long as there is enough disk space and file size does not exceed the allowed maximum length Paolo > Now I have significantly reduce them but I have the same problem. I > use Quantum Espresso 5.1 and I work with 64 CPUs. > > > I attach the input files for the pwx calculation and for the head one. > > > Any help will be really appreciated. > > > Thank you very much > > > Valentina Cantatore > PostDoc@Università del Piemonte Orientale, Alessandria > ___ > Pw_forum mailing list > Pw_forum@pwscf.org > http://pwscf.org/mailman/listinfo/pw_forum -- Paolo Giannozzi, Dept. Chemistry&Physics&Environment, Univ. Udine, via delle Scienze 208, 33100 Udine, Italy Phone +39-0432-558216, fax +39-0432-558222 ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum
[Pw_forum] Binding energy of Ti on Graphene oxide sheet
I was going through the paper "wang et. al. ACS nano Vol3, No.10, 2995-3000, (2009)" where the binding energy of Titanium on Graphene oxide (figure:3) was done using below mentioned formula: Eb (Ti) = E(GO) + E(Ti) - E(Ti/GO) Here I have a confusion, as for E(GO) some of the oxygen atoms are double bonded with the Graphene sheet, but in E(Ti/GO) few oxygen breaks one of the bond from the sheet and get attached to Ti atom. So here the final structure of Ti-with-GO is completely different. So my question is that is the way of calculating the Binding energy of Ti on Grapehene oxide is correct? If yes then can anyone explain this? With best regards, Rajiv Kumar Chouhan, Post-Doctoral Fellow, Boise State University, Idhao-83725 ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum
Re: [Pw_forum] Convergence of Magnetization in Graphene Monovacancy Supercell
Dear Haricharan Padmanabhan The magnetization asociated with a vacancy is known to converge very slowly. As you will see in the following detailed study: PHYSICAL REVIEW B 85, 245443 (2012) the 6x6 supercell in in fact very small... if you want to get your magnetization converged. 2d systems can have some advantages but also some serious drawbacks due to the very slow convergence of certain quantities related to the bi-dimensionality. This is also why tight-binding is very popular in graphene :-) good luck Cyrille -- Cyrille Barreteau CEA Saclay, IRAMIS, SPEC Bat. 771 91191 Gif sur Yvette Cedex, FRANCE DTU Nanotech Ørsteds Plads, building 345E DK-2800 Kgs. Lyngby, DENMARK +33 1 69 08 29 51 / +33 6 47 53 66 52 (mobile) (Fr) +4545 25 63 12/ +45 28 72 55 18 (mobile) (Dk) email: cyrille.barret...@cea.fr / cyr...@nanotech.dtu.dk Web: http://iramis.cea.fr/Pisp/cyrille.barreteau/ --- De : pw_forum-boun...@pwscf.org [pw_forum-boun...@pwscf.org] de la part de Haricharan Padmanabhan [hari00...@gmail.com] Envoyé : mardi 21 octobre 2014 10:43 À : pw_forum@pwscf.org Objet : [Pw_forum] Convergence of Magnetization in Graphene Monovacancy Supercell Dear Quantum ESPRESSO users, I am attempting to estimate the value of the magnetism in Graphene with a mono-vacancy, using supercells of different sizes. Some background - - One would expect (from literature) the magnetism to converge to around 1.5 bohr magnetons (uB) as the supercell size is increased. - Since vacancies result in localized states at the Fermi level (flat bands, or peaks in the DOS), a dense k-point mesh is usually required to accurately estimate (N.up - N.down), and hence the magnetism. I first obtained convergence with respect to k-point sampling, for a 4x4 supercell (31 atoms + 1 vacancy) K-point meshTotal Energy (Ry) Total magnetization (uB) 16x16 -355.5861.29 20x20 -355.5861.21 24x24 -355.5861.25 32x32 -355.5861.27 36x36 -355.5861.27 A larger 6x6 supercell (71 atoms + 1 vacancy), by conventional wisdom, would require a less dense k-point mesh for convergence. However, even with a dense 32x32 k-point mesh, I get a non-converged value of 0.59 uB for the magnetism. Different calculations with different k-point meshes give me values that oscillate between 0.59 and 1.45 uB, with no apparent pattern. It does not make sense to me to further increase the k-point mesh density. Clearly, the flat bands at the Fermi level are causing trouble depending on whether they've been bumped slightly above or below the Fermi level, due to inadequate k-point sampling in different calculations. How can I fix this problem? Will doing a manual k-point sampling help? A part of the input file - &system ibrav= 4, celldm(1) =27.9, celldm(3) = 1, nat= 71, ntyp= 1, ecutwfc =30.0, ecutrho = 250.0, occupations='smearing', smearing='gaussian', degauss=0.001 nspin = 2, starting_magnetization(1)=0.7 / &electrons diagonalization='cg' mixing_mode = 'plain' mixing_beta = 0.1 conv_thr = 1.0d-6 electron_maxstep = 200 / ATOMIC_SPECIES C 12.011 c_pbe_v1.2.uspp.F.UPF K_POINTS {automatic} 32 32 1 0 0 0 A part of the output file - the Fermi energy is-1.9682 ev total energy =-815.17816366 Ry Harris-Foulkes estimate =-815.17815922 Ry estimated scf accuracy< 0.0077 Ry The total energy is the sum of the following terms: one-electron contribution = -5427.83442348 Ry hartree contribution =2763.25828072 Ry xc contribution =-257.55564014 Ry ewald contribution=2106.95386447 Ry smearing contrib. (-TS) = -0.00024524 Ry total magnetization = 0.59 Bohr mag/cell absolute magnetization= 0.79 Bohr mag/cell Thank you. Haricharan Padmanabhan Indian Institute of Technology Madras ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum
[Pw_forum] Quantum Espresso for Solid-Solid interfaces?
Hi All, I would like to know whether Quantum Espresso can be used to study the interfaces of a solar cell. Thanks in advance for the replies. Regards Daniel ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum
[Pw_forum] Error in davcio running head.x
Dear QE users, I'm here to ask again for your help because I have problems running head.x program. The program stops with the error: "Error in routine davcio (25): error while writing from file "*/./out/_ph0/*.prd38". I had a similar problem with a calculation on a molecular system and you suggested me to reduce the cutoffs. It worked in that case. Now I have significantly reduce them but I have the same problem. I use Quantum Espresso 5.1 and I work with 64 CPUs. I attach the input files for the pwx calculation and for the head one. Any help will be really appreciated. Thank you very much Valentina Cantatore PostDoc@Università del Piemonte Orientale, Alessandria MAPbI3_beta_20_100_head.inp Description: Binary data MAPbI3_beta_20_100_scf.inp Description: Binary data ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum
Re: [Pw_forum] nqx=1 in input but full grid in output
On 10/21/2014 04:49 PM, Roberto Gaspari wrote: EXX: grid of k+q point setup nkqs = 42 that is the grid for the Fock operator is as dense as the regular Monkhorst-Pack grid. Does all this correspond to an expected behavior of pwscf? Yes it does. Well, I think it does, you do not say how many irreducible k-point you have in your system. nqX=1 means that wfcs at each kpoint only exchange with wfcs at the same kpoint. What you ar thinking is having wfcs at any k-point only exchange with wfcs at the Gamma point. A big limiting factor with EXX calculations is that CPU time scales with the square of the number of k-points. By setting nqX to a fixed value the scaling becomes linear again when nk is bigger than nq. -- Dr. Lorenzo Paulatto IdR @ IMPMC -- CNRS & Université Paris 6 +33 (0)1 44 275 084 / skype: paulatz http://www.impmc.upmc.fr/~paulatto/ 23-24/4é16 Boîte courrier 115, 4 place Jussieu 75252 Paris Cédex 05 ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum
Re: [Pw_forum] Issue while executing QE-5.0 GPU
Hi Filippo, As per your suggestion I ran the not-accelerated version of QE for same input data , it worked well for me. Following is the contents of make.sys file, used for QE GPU compilation. Please let me know what are the other details required to help me in this issue. # MANUAL_DFLAGS = -D__ISO_C_BINDING -D__DISABLE_CUDA_NEWD -D__DISABLE_CUDA_ADDUSDENS DFLAGS = -D__INTEL -D__FFTW3 -D__MPI -D__PARA -D__SCALAPACK -D__CUDA -D__PHIGEMM -D__OPENMP $(MANUAL_DFLAGS) FDFLAGS= $(DFLAGS) # IFLAGS = how to locate directories where files to be included are # In most cases, IFLAGS = -I../include IFLAGS = -I../include -I/opt/app/espresso-5.0.2-gpu-14.03/espresso-5.0.2/GPU/..//phiGEMM/include -I/opt/CUDA-5.5/include # MOD_FLAGS = flag used by f90 compiler to locate modules # Each Makefile defines the list of needed modules in MODFLAGS MOD_FLAG = -I # Compilers: fortran-90, fortran-77, C # If a parallel compilation is desired, MPIF90 should be a fortran-90 # compiler that produces executables for parallel execution using MPI # (such as for instance mpif90, mpf90, mpxlf90,...); # otherwise, an ordinary fortran-90 compiler (f90, g95, xlf90, ifort,...) # If you have a parallel machine but no suitable candidate for MPIF90, # try to specify the directory containing "mpif.h" in IFLAGS # and to specify the location of MPI libraries in MPI_LIBS MPIF90 = mpiifort #F90 = ifort CC = mpiicc F77= mpiifort # C preprocessor and preprocessing flags - for explicit preprocessing, # if needed (see the compilation rules above) # preprocessing flags must include DFLAGS and IFLAGS CPP= cpp CPPFLAGS = -P -traditional $(DFLAGS) $(IFLAGS) # compiler flags: C, F90, F77 # C flags must include DFLAGS and IFLAGS # F90 flags must include MODFLAGS, IFLAGS, and FDFLAGS with appropriate syntax CFLAGS = -DMKL_ILP64 -O3 $(DFLAGS) $(IFLAGS) F90FLAGS = $(FFLAGS) -nomodule -fpp $(FDFLAGS) $(IFLAGS) $(MODFLAGS) FFLAGS = -i8 -O2 -assume byterecl -g -traceback -par-report0 -vec-report0 # compiler flags without optimization for fortran-77 # the latter is NEEDED to properly compile dlamch.f, used by lapack FFLAGS_NOOPT = -i8 -O0 -assume byterecl -g -traceback # compiler flag needed by some compilers when the main is not fortran # Currently used for Yambo FFLAGS_NOMAIN = -nofor_main # Linker, linker-specific flags (if any) # Typically LD coincides with F90 or MPIF90, LD_LIBS is empty LD = mpiifort LDFLAGS= -ilp64 LD_LIBS= -L/opt/CUDA-5.5/lib64 -lcublas -lcufft -lcudart # External Libraries (if any) : blas, lapack, fft, MPI # If you have nothing better, use the local copy : # BLAS_LIBS = /your/path/to/espresso/BLAS/blas.a # BLAS_LIBS_SWITCH = internal BLAS_LIBS = /opt/app/espresso-5.0.2-gpu-14.03/espresso-5.0.2/GPU/..//phiGEMM/lib/libphigemm.a -L/opt/intel/composer_xe_2013.1.117/mkl/lib/intel64 -lmkl_intel_ilp64 -lmkl_intel_thread -lmkl_core -liomp5 -lpthread -lm BLAS_LIBS_SWITCH = external # If you have nothing better, use the local copy : # LAPACK_LIBS = /your/path/to/espresso/lapack-3.2/lapack.a # LAPACK_LIBS_SWITCH = internal # For IBM machines with essl (-D__ESSL): load essl BEFORE lapack ! # remember that LAPACK_LIBS precedes BLAS_LIBS in loading order # CBLAS is used in case the C interface for BLAS is missing (i.e. ACML) CBLAS_ENABLED = 0 LAPACK_LIBS= LAPACK_LIBS_SWITCH = external ELPA_LIBS_SWITCH = disabled SCALAPACK_LIBS = -lmkl_scalapack_ilp64 -lmkl_blacs_intelmpi_ilp64 # nothing needed here if the the internal copy of FFTW is compiled # (needs -D__FFTW in DFLAGS) FFT_LIBS = -L/opt/intel/composer_xe_2013.1.117/mkl/lib/intel64 # For parallel execution, the correct path to MPI libraries must # be specified in MPI_LIBS (except for IBM if you use mpxlf) MPI_LIBS = # IBM-specific: MASS libraries, if available and if -D__MASS is defined in FDFLAGS MASS_LIBS = # ar command and flags - for most architectures: AR = ar, ARFLAGS = ruv AR = ar ARFLAGS= ruv # ranlib command. If ranlib is not needed (it isn't in most cases) use # RANLIB = echo RANLIB = ranlib # all internal and external libraries - do not modify FLIB_TARGETS = all # CUDA section NVCC = /opt/CUDA-5.5/bin/nvcc NVCCFLAGS= -O3 -gencode arch=compute_20,code=sm_20 -gencode arch=compute_20,code=sm_21 PHIGEMM_INTERNAL = 1 PHIGEMM_SYMBOLS = 1 MAGMA_INTERNAL = 0 LIBOBJS= ../flib/ptools.a ../flib/flib.a ../clib/clib.a ../iotk/src/libiotk.a LIBS = $(SCALAPACK_LIBS) $(LAPACK_LIBS) $(FFT_LIBS) $(BLAS_LIBS) $(MPI_LIBS) $(MASS_LIBS) $(LD_LIBS) # wget or curl - useful to download from network WGET = wget -O ## "Apologizing d
[Pw_forum] nqx=1 in input but full grid in output
Dear all, I am performing my first hybrid functional calculations with PWSCF. I was trying to simulate a quite large system (24 at/unit cell volume=2082.0010 a.u.^3) on a large machine (CINECA-Fermi). The scf appears quite slow so I was trying to test the convergence of the grid density for the Fock operator, to see if I can be any faster without losing too much accuracy. Following the EXX examples I set in the &system section &system ecutwfc = 70, ecutrho = 280, occupations = 'smearing', degauss = 0.01, input_dft='pbe0', nqx1 = 1, nqx2 = 1, nqx3 = 1, / and for the regular Monkhorst-Pack grid: / K_POINTS (automatic) 3 3 3 1 1 1 In the output file I obtain a Monkhorst-Pack of 42 k-points, which is fine. Anyway I was expecting to get something like EXX: grid of k+q point setup nkqs = 1 since, as far as I have understood, setting all nqxs to 1 amounts to performing a q=0 calculation I get, instead: EXX: grid of k+q point setup nkqs = 42 that is the grid for the Fock operator is as dense as the regular Monkhorst-Pack grid. Does all this correspond to an expected behavior of pwscf? I thank all of you for your attention, Best Regards, Roberto Gaspari, Italian Institute of Technology, Concept Lab ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum
[Pw_forum] electric field
Hi, I am doing an optimization including an external electric field using the SVN pwscf. I am getting the following error after the first iteration of the second scf geometry: extrapolated charge 192.39606, renormalised to 189.0 Atomic wfc used for LDA+U Projector are NOT orthogonalized total cpu time spent up to now is22601.5 secs per-process dynamical memory: 718.8 Mb Self-consistent Calculation iteration # 1 ecut= 100.00 Ry beta=0.30 %% Error in routine gk_sort (1): array gk out-of-bounds %% stopping ... Here is my input file: &control prefix='job', calculation = "vc-relax", restart_mode = 'from_scratch', verbosity = 'high', tstress = .true., tprnfor = .true., nstep = 100, etot_conv_thr = 1.0d-6, forc_conv_thr = 1.0d-5, iprint = 1, max_seconds = 432000, ! 5 days lelfield=.true., nberrycyc=1, / &system ibrav= 6, celldm(1)=15.8610666, celldm(3)= 1.0139966, nat= 39, ntyp= 4, input_dft=wc !nbnd = 220, !189 electrons, ecutwfc = 100.0, !occupations='smearing', smearing='gauss', degauss=0.003, !occupations='tetrahedra', nspin=2, tot_magnetization= 5.0, !starting_magnetization(1)= 0.0, !starting_magnetization(2)= 0.0, !starting_magnetization(3)= 0.0, !starting_magnetization(4)= 1.0, lda_plus_u = .true., Hubbard_U(4)=6, Hubbard_J0(4)=0.6, !U_projection_type='file' starting_ns_eigenvalue(1,1,4)=1.d0, starting_ns_eigenvalue(2,1,4)=1.d0, starting_ns_eigenvalue(3,1,4)=1.d0, starting_ns_eigenvalue(4,1,4)=1.d0, starting_ns_eigenvalue(5,1,4)=1.d0, starting_ns_eigenvalue(1,2,4)=0.d0, starting_ns_eigenvalue(2,2,4)=0.d0, starting_ns_eigenvalue(3,2,4)=0.d0, starting_ns_eigenvalue(4,2,4)=0.d0, starting_ns_eigenvalue(5,2,4)=0.d0, / &electrons conv_thr = 1.0d-7 electron_maxstep=300, mixing_beta=0.3, startingwfc='random' efield_cart(1)=0.027,efield_cart(2)=0.d0,efield_cart(3)=0.d0 !efield_phase='read' / &IONS / &CELL cell_dynamics = 'bfgs', / ATOMIC_SPECIES ... ATOMIC_POSITIONS {crystal} ... K_POINTS {automatic} 4 4 4 0 0 0 My job script: mpirun -np 64 /u/home/jnossa/PRO/svnespresso-5.1/bin/pw.x printopt I reduced the kpoits grid to 2x2x2 but got the same error. how can I solve this problem? Thanks. -- With best regards, Javier Francisco Nossa Postdoc at Geophysical Laboratory Carnegie Institution of Washington 5251 Broad Branch Road, N.W. Washington, DC 20015-1305 Tel.: 1.240.476.3993 E-mail: jno...@carnegiescience.edu ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum
Re: [Pw_forum] Band structure calculation with external electric field.
Dear Barnali Bhattacharya, I think you can fully relax (vc-relax) the structure without the field firstly to get the optimized result. Then, you can just relax adding the field. Lastly, it needs to test the results before and after adding field in your bands calculation. Best wishes P. L. Gong ISSP, China > -原始邮件- > 发件人:"Barnali Bhattacharya" > 发送时间:2014年10月21日 星期二 > 收件人:pw_forum@pwscf.org > 抄送: > 主题:[Pw_forum] Band structure calculation with external electric field. > > > > Dear QE user, > I am a new user of QE. I want to calculate the band structure of bi-layer > graphene by employing external electric field. I have done the > scfcalculations without electric field, then again did the scfcalculation > with an electric field included in the z-direction(efield_cart (1) = 0. d0, > efield_cart (2)=0.d0, > efield_cart(3) = 0.001d0,). Then I have done the nscfcalculations with > electric field. Now I have to calculate the bandscalculation. But I am > confused about the step. Now my question is– > Ø1) Is it necessary to optimize (vc-relaxed) the structure with an electric > field before performing the scfcalculation? > Ø2) In the band calculation am I include the ‘lelfield=.true.’ option? > > Could anyone please guide me and share their experience? > I am waiting for positive response > Thanking you in advance. > > Sincerely > barnali -- Addr: Institute of Solid State Physics, Chinese Academy of Sciences, Hefei, Anhui 230031, China Tel: +86-551-65591591(office), 18756086113(cell phone) Email: plg...@theory.issp.ac.cn ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum
Re: [Pw_forum] Convergence of Magnetization in Graphene Monovacancy Supercell
On 10/21/2014 10:43 AM, Haricharan Padmanabhan wrote: > Clearly, the flat bands at the Fermi level are causing trouble > depending on whether they've been bumped slightly above or below the > Fermi level, due to inadequate k-point sampling in different > calculations. How can I fix this problem? Will doing a manual k-point > sampling help? Are you increasing the inter-layer space in the larger cell? I cannot tell from the tiny bit of input file you provide. If you do, don't. Too much vacuum space makes the calculation difficult to converge and you may even get electrons in the vacuum. About 6 or 7 Angstroms of vacuum is enough. best regards -- Dr. Lorenzo Paulatto IdR @ IMPMC -- CNRS & Université Paris 6 +33 (0)1 44 275 084 / skype: paulatz http://www.impmc.upmc.fr/~paulatto/ 23-24/4é16 Boîte courrier 115, 4 place Jussieu 75252 Paris Cédex 05 ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum
Re: [Pw_forum] Electric field in silicene
I think the Ecut is small. Did you test the its convergence to total energy? Otherwise, your large electric field maybe lead to the convergence harder. Try large Ecut and small field, good luck! 在2014-10-21 18:11:15,plgongplg...@theory.issp.ac.cn写道: Dear all, I am wanting to get the Dos of silicene under the effect of an external electric field. I have done the scf calculations without electric field , then again did the scf calculation with an electric field included in the z-direction (with value 0.008ua). But the convergence is not achieved and it stopped after 800 iterations and giving it this message: "total cpu time spent up to now is 20409.6 secs total energy = -64.27063591 Ry Harris-Foulkes estimate = -62.93460760 Ry estimated scf accuracy < 0.3422 Ry End of self-consistent calculation convergence NOT achieved after 800 iterations: stopping" You will find below in file for the scf calculation when an electric field is applied: &control calculation='scf' restart_mode='from_scratch', prefix='elec0.08', lelfield=.true., nberrycyc=3 pseudo_dir ='/home/siham/Desktop/espresso-5.0.1-GPU/pseudo', outdir='/home/siham/Desktop/espresso-5.0.1-GPU/tmp' / &system ibrav= 1, celldm(1)=10.18, nat= 8, ntyp= 1, ecutwfc = 20.0 / &electrons electron_maxstep=800, diagonalization='david', conv_thr = 1.0d-8, mixing_beta = 0.5, startingwfc='random', efield_cart(1)=0.d0,efield_cart(2)=0.d0,efield_cart(3)=0.008d0 / ATOMIC_SPECIES Si 28.086 Si.pbe-rrkj.UPF ATOMIC_POSITIONS Si -0.125 -0.125 -0.125 Si 0.375 0.375 -0.125 Si 0.375 -0.125 0.375 Si -0.125 0.375 0.375 Si 0.125 0.125 0.125 Si 0.625 0.625 0.125 Si 0.625 0.125 0.625 Si 0.125 0.625 0.625 K_POINTS {automatic} 3 3 7 0 0 0 Thanks in advance ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum
[Pw_forum] Band structure calculation with external electric field.
Dear QE user, I am a new user of QE. I want to calculate the band structure of bi-layer graphene by employing external electric field. I have done the scf calculations without electric field, then again did the scf calculation with an electric field included in the z-direction (efield_cart (1) = 0. d0, efield_cart (2)=0.d0, efield_cart(3) = 0.001d0,). Then I have done the nscf calculations with electric field. Now I have to calculate the bands calculation. But I am confused about the step. Now my question is – Ø 1) Is it necessary to optimize (vc-relaxed) the structure with an electric field before performing the scf calculation? Ø 2) In the band calculation am I include the ‘lelfield = . true.’ option? Could anyone please guide me and share their experience? I am waiting for positive response Thanking you in advance. Sincerely barnali ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum
[Pw_forum] Electric field in silicene
Dear all, I am wanting to get the Dos of silicene under the effect of an external electric field. I have done the scf calculations without electric field , then again did the scf calculation with an electric field included in the z-direction (with value 0.008ua). But the convergence is not achieved and it stopped after 800 iterations and giving it this message: "total cpu time spent up to now is 20409.6 secs total energy = -64.27063591 Ry Harris-Foulkes estimate = -62.93460760 Ry estimated scf accuracy < 0.3422 Ry End of self-consistent calculation convergence NOT achieved after 800 iterations: stopping" You will find below in file for the scf calculation when an electric field is applied: &control calculation='scf' restart_mode='from_scratch', prefix='elec0.08', lelfield=.true., nberrycyc=3 pseudo_dir ='/home/siham/Desktop/espresso-5.0.1-GPU/pseudo', outdir='/home/siham/Desktop/espresso-5.0.1-GPU/tmp' / &system ibrav= 1, celldm(1)=10.18, nat= 8, ntyp= 1, ecutwfc = 20.0 / &electrons electron_maxstep=800, diagonalization='david', conv_thr = 1.0d-8, mixing_beta = 0.5, startingwfc='random', efield_cart(1)=0.d0,efield_cart(2)=0.d0,efield_cart(3)=0.008d0 / ATOMIC_SPECIES Si 28.086 Si.pbe-rrkj.UPF ATOMIC_POSITIONS Si -0.125 -0.125 -0.125 Si 0.375 0.375 -0.125 Si 0.375 -0.125 0.375 Si -0.125 0.375 0.375 Si 0.125 0.125 0.125 Si 0.625 0.625 0.125 Si 0.625 0.125 0.625 Si 0.125 0.625 0.625 K_POINTS {automatic} 3 3 7 0 0 0 Thanks in advance ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum
[Pw_forum] Convergence of Magnetization in Graphene Monovacancy Supercell
Dear Quantum ESPRESSO users, I am attempting to estimate the value of the magnetism in Graphene with a mono-vacancy, using supercells of different sizes. Some background - - One would expect (from literature) the magnetism to converge to around 1.5 bohr magnetons (uB) as the supercell size is increased. - Since vacancies result in localized states at the Fermi level (flat bands, or peaks in the DOS), a dense k-point mesh is usually required to accurately estimate (N.up - N.down), and hence the magnetism. I first obtained convergence with respect to k-point sampling, for a 4x4 supercell (31 atoms + 1 vacancy) K-point mesh Total Energy (Ry) Total magnetization (uB) 16x16 -355.586 1.29 20x20 -355.586 1.21 24x24 -355.586 1.25 32x32 -355.586 1.27 36x36 -355.586 1.27 A larger 6x6 supercell (71 atoms + 1 vacancy), by conventional wisdom, would require a less dense k-point mesh for convergence. However, even with a dense 32x32 k-point mesh, I get a non-converged value of 0.59 uB for the magnetism. Different calculations with different k-point meshes give me values that oscillate between 0.59 and 1.45 uB, with no apparent pattern. It does not make sense to me to further increase the k-point mesh density. Clearly, the flat bands at the Fermi level are causing trouble depending on whether they've been bumped slightly above or below the Fermi level, due to inadequate k-point sampling in different calculations. How can I fix this problem? Will doing a manual k-point sampling help? A part of the input file - &system ibrav= 4, celldm(1) =27.9, celldm(3) = 1, nat= 71, ntyp= 1, ecutwfc =30.0, ecutrho = 250.0, occupations='smearing', smearing='gaussian', degauss=0.001 nspin = 2, starting_magnetization(1)=0.7 / &electrons diagonalization='cg' mixing_mode = 'plain' mixing_beta = 0.1 conv_thr = 1.0d-6 electron_maxstep = 200 / ATOMIC_SPECIES C 12.011 c_pbe_v1.2.uspp.F.UPF K_POINTS {automatic} 32 32 1 0 0 0 A part of the output file - the Fermi energy is-1.9682 ev total energy =-815.17816366 Ry Harris-Foulkes estimate =-815.17815922 Ry estimated scf accuracy< 0.0077 Ry The total energy is the sum of the following terms: one-electron contribution = -5427.83442348 Ry hartree contribution =2763.25828072 Ry xc contribution =-257.55564014 Ry ewald contribution=2106.95386447 Ry smearing contrib. (-TS) = -0.00024524 Ry total magnetization = 0.59 Bohr mag/cell absolute magnetization= 0.79 Bohr mag/cell Thank you. Haricharan Padmanabhan Indian Institute of Technology Madras ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum