Dear Dingfu, Thank you for your reply (LOL).
After making some tests, I find this error is not caused by the occupations tag. The PBE pseudopotential cannot accurately reproduce the property of the slab. I switched to pw91 as you said, and it works fine now. Thanks for your discussion with me. Bests Fang 2016-04-23 9:19 GMT+09:00 Dingfu Shao <[email protected]>: > Hi, Yue-Wen, > > You need to set occupations='fixed' for insulator. 'Smearing' is for > metal. > > Best regards, > > Ding-Fu > > > > > *Ding-Fu Shao, Ph. D.* > > > *Department of Physics and Astronomy, University of Nebraska-Lincoln* > > *Lincoln, NE **68588-0299* > > *Email: [email protected] <[email protected]>* > > 2016-04-22 4:43 GMT-05:00 Yue-Wen Fang <[email protected]>: > >> Dear all, >> >> I calculated a MgO slab model with two* symmetrical* interface using 3 >> different DFT codes using plane wave method. The other two shows this slab >> is an insulator, and the results are almost completely same. >> >> However, pwscf calculation show it is a metal with an unexpected Fermi >> shift in the density of states although the shape of DOS is similar to >> those obtained from other DFTcodes. I think this is caused my incorrect >> settings, but I haven't found what specific factor causes this error. >> >> The scf and nscf input files are shown in the last part, hopefully >> experts could give some suggestions. Many thanks. >> >> *PS:* >> Because it is just a test, I only used about 6 Angstrom in this model. I >> checked the potential in every DFT code, there is no slope of potential in >> vacuum, which indicates there is no unexpected artificial field is induced. >> >> >> *SCF calculation input:* >> >> &control >> calculation = 'scf', >> verbosity = 'high', >> restart_mode = 'from_scratch', >> prefix = 'mgo', >> tstress = .false., >> tprnfor = .false., >> pseudo_dir = '.', >> outdir = '.' >> wf_collect=.true. >> / >> &system >> ibrav=0, nat=6, ntyp=2, >> ecutwfc=25, >> ecutrho=300, >> occupations='smearing', >> smearing='gaussian', >> degauss=0.001, >> / >> &electrons >> diagonalization='david', >> mixing_mode = 'plain', >> mixing_beta = 0.7, >> conv_thr = 1.0d-7, >> / >> ATOMIC_SPECIES >> Mg 24.305000 Mg.pbe-nsp-bpaw.UPF >> O 15.999400 O.pbe-van_ak.UPF >> ATOMIC_POSITIONS crystal >> Mg 0.000000 0.000000 0.370955 >> Mg 0.500000 0.500000 0.500000 >> Mg 0.000000 0.000000 0.629045 >> O 0.500000 0.500000 0.370955 >> O 0.000000 0.000000 0.500000 >> O 0.500000 0.500000 0.629045 >> K_POINTS {Automatic} >> 7 7 1 0 0 0 >> CELL_PARAMETERS bohr >> 5.627166 0.000000 0.000000 >> 0.000000 5.627166 0.000000 >> 0.000000 0.000000 30.834283 >> >> >> *NSCF calculation input:* >> >> &control >> calculation = 'nscf', >> verbosity = 'high', >> restart_mode = 'from_scratch', >> prefix = 'mgo', >> tstress = .false., >> tprnfor = .false., >> pseudo_dir = '.', >> outdir = '.' >> wf_collect=.true. >> / >> &system >> ibrav=0, nat=6, ntyp=2, >> ecutwfc=25, >> ecutrho=300, >> occupations='tetrahedra', >> / >> &electrons >> diagonalization='david', >> mixing_mode = 'plain', >> mixing_beta = 0.7, >> conv_thr = 1.0d-7, >> / >> ATOMIC_SPECIES >> Mg 24.305000 Mg.pbe-nsp-bpaw.UPF >> O 15.999400 O.pbe-van_ak.UPF >> ATOMIC_POSITIONS crystal >> Mg 0.000000 0.000000 0.370955 >> Mg 0.500000 0.500000 0.500000 >> Mg 0.000000 0.000000 0.629045 >> O 0.500000 0.500000 0.370955 >> O 0.000000 0.000000 0.500000 >> O 0.500000 0.500000 0.629045 >> K_POINTS {Automatic} >> 11 11 2 0 0 0 >> CELL_PARAMETERS bohr >> 5.627166 0.000000 0.000000 >> 0.000000 5.627166 0.000000 >> 0.000000 0.000000 30.834283 >> >> -- >> >> ------------------------------------------------------------------------------------------------------------ >> Yue-Wen FANG, PhD student >> East China Normal University <http://english.ecnu.edu.cn/>, China >> Japan Fine Ceramics Center, Japan >> >> >> >> >> _______________________________________________ >> Pw_forum mailing list >> [email protected] >> http://pwscf.org/mailman/listinfo/pw_forum >> > > > _______________________________________________ > Pw_forum mailing list > [email protected] > http://pwscf.org/mailman/listinfo/pw_forum > -- ------------------------------------------------------------------------------------------------------------ Yue-Wen FANG, PhD student East China Normal University <http://english.ecnu.edu.cn/>, China Japan Fine Ceramics Center, Japan
_______________________________________________ Pw_forum mailing list [email protected] http://pwscf.org/mailman/listinfo/pw_forum
