Hello all, I am trying to calculate the Wannier functions (WF) associated with the valence bands of diamond. For future applications, I have to make this calculation using spin up and down channels separately and use only the gamma point.
Diamond is a very simple system with high symmetry, so I simulate only the unit cell (slightly different than the examples that come with Wannier90 package). With 8 atoms in the unit cell, 32 valence electrons, and 16 distinct C-C bonds, I expect 16 WF for both the spin up and down channels. These WF should be located on these C-C atoms. 1 spin up and 1 spin down at each of them. My results also confirm this expectation except for a problem I cannot seem to get rid of. Even though everything looks fine at first glance, when plotted, everything with respect to spin up channel behaves as expected. But when I plot spin down WF, they're neither located where they're supposed to be nor do they look like what they're supposed to look like. I would appreciate your thoughts on this matter. Thank you, Anil Bilgin PhD candidate Pritzker School of Molecular Engineering University of Chicago *Details below this line* I'm using QE version 6.1+intelmpi-5.1+intel-16.0 Here's what some input files look like. I can provide more information about outputs as well if necessary. *First an scf run:* &CONTROL calculation = 'scf' prefix='di' pseudo_dir='/project2/ahigh/bilgin/Rydberg_project/pseudo_potentials' outdir='./' verbosity = 'high' wf_collect = .TRUE. tstress=.TRUE. tprnfor=.TRUE. forc_conv_thr = 1.0D-5 / &SYSTEM ibrav = 0 ecutwfc = 90 tot_charge = 0 nspin = 2 tot_magnetization = 0 nbnd = 16 nat = 8 ntyp = 1 / &ELECTRONS conv_thr = 1D-08 diagonalization='cg' mixing_mode = 'plain' mixing_beta = 0.7 / K_POINTS gamma CELL_PARAMETERS angstrom 3.568006 0.000000 0.000000 0.000000 3.568006 0.000000 0.000000 0.000000 3.568006 ATOMIC_SPECIES C 12.01099968 C_ONCV_PBE-1.0.upf ATOMIC_POSITIONS crystal C 0.00000000 0.00000000 0.00000000 C 0.25000000 0.25000000 0.25000000 C 0.50000000 0.50000000 0.00000000 C 0.75000000 0.75000000 0.25000000 C 0.50000000 0.00000000 0.50000000 C 0.75000000 0.25000000 0.75000000 C 0.00000000 0.50000000 0.50000000 C 0.25000000 0.75000000 0.75000000 *Secondly, an nscf run with an almost identical input:* &CONTROL calculation = 'nscf' prefix='di' pseudo_dir='/project2/ahigh/bilgin/Rydberg_project/pseudo_potentials' outdir='./' verbosity = 'high' wf_collect = .TRUE. tstress=.TRUE. tprnfor=.TRUE. forc_conv_thr = 1.0D-5 / &SYSTEM ibrav = 0 ecutwfc = 90 tot_charge = 0 nspin = 2 tot_magnetization = 0 nbnd = 24 nat = 8 ntyp = 1 / &ELECTRONS conv_thr = 1D-08 / K_POINTS gamma CELL_PARAMETERS angstrom 3.568006 0.000000 0.000000 0.000000 3.568006 0.000000 0.000000 0.000000 3.568006 ATOMIC_SPECIES C 12.01099968 C_ONCV_PBE-1.0.upf ATOMIC_POSITIONS crystal C 0.00000000 0.00000000 0.00000000 C 0.25000000 0.25000000 0.25000000 C 0.50000000 0.50000000 0.00000000 C 0.75000000 0.75000000 0.25000000 C 0.50000000 0.00000000 0.50000000 C 0.75000000 0.25000000 0.75000000 C 0.00000000 0.50000000 0.50000000 C 0.25000000 0.75000000 0.75000000 *Third step is the normal* wannier90.x -pp pristine-unit-up wannier90.x -pp pristine-unit-dn *Then fourth step* pw2wannier90.x < pristine-unit-up.pw2wan > pw2wan-up.out pw2wannier90.x < pristine-unit-dn.pw2wan > pw2wan-dn.out with the two .pw2wan files for spin up and down as follows: &inputpp outdir = './' prefix = 'di' seedname = 'pristine-unit-dn' spin_component = 'down' write_mmn = .true. write_amn = .true. write_unk = .true. / &inputpp outdir = './' prefix = 'di' seedname = 'pristine-unit-up' spin_component = 'up' write_mmn = .true. write_amn = .true. write_unk = .true. / And finally the .win input files are identical (between spin up and down) num_bands = 24 num_wann = 16 num_iter = 140 iprint = 3 translate_home_cell = .true. write_xyz = .true. wannier_plot = .true. wannier_plot_supercell = 1 begin projections random end projections mp_grid : 1 1 1 gamma_only : true begin kpoints 0.0 0.0 0.0 end kpoints begin atoms_frac C 0.00000000 0.00000000 0.0000000 C 0.25000000 0.25000000 0.2500000 C 0.50000000 0.50000000 0.0000000 C 0.75000000 0.75000000 0.2500000 C 0.50000000 0.00000000 0.5000000 C 0.75000000 0.25000000 0.7500000 C 0.00000000 0.50000000 0.5000000 C 0.25000000 0.75000000 0.7500000 end atoms_frac begin unit_cell_cart bohr 6.7425540 0.0000000 0.0000000 0.0000000 6.7425540 0.0000000 0.0000000 0.0000000 6.7425540 end unit_cell_cart *And finally I do* wannier90.x pristine-unit-up wannier90.x pristine-unit-dn
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