<div dir="ltr"><div><div><div>Dear wannier users,<br><br></div><div>I would like to ask whether the following input for conductivity tensor calculation looks ok. <br><br>num_bands = 128 ! set to NBANDS by VASP<br> num_wann = 88<br> begin projections<br> Mo:d ! 20<br> Te:p ! 24<br> end projections<br><br>###########BoltzWann ############<br>boltzwann = true<br>kmesh = 400 400 400<br>boltz_relax_time = 0.001<br>boltz_mu_min = 7.95123782 <wbr> #ef-def<br>boltz_mu_max = 8.35123782<br>boltz_mu_step = 0.04<br>boltz_temp_min = 2<br>boltz_temp_max = 10<br>boltz_temp_step = 2<br>boltz_tdf_energy_step=0.01<br>boltz_tdf_smr_fixed_en_width = 0.01<br>boltz_tdf_smr_type = gauss<br>boltz_calc_also_dos = true<br>boltz_dos_energy_min = 5.0<br>boltz_dos_energy_max = 15.0<br>boltz_dos_energy_step = 0.01<br>##############################<wbr>###<br><br>write_hr = .true.<br># Bandstructure<br> restart = plot<br> bands_plot = true<br> begin kpoint_path<br>....<br> end kpoint_path<br> bands_num_points 100 # bands_plot_format gnuplot<br><br><br>spinors = .true.<br><br>begin unit_cell_cart<br><div> 3.4716802 0.0000000 0.0000000 /*this and the next line changes*/<br></div><div> 0.0000000 6.3666750 0.0000000 /*accordingly for different cases*/<br></div> 0.0000000 0.0000000 13.8452386<br>end unit_cell_cart<br><br>begin atoms_cart<br>...<br>end atoms_cart<br><br>mp_grid = 12 6 3 /*this line differs from each case*/<br><br>begin kpoints<br>...<br>end kpoints<br><br></div><div>This input returns reasonable result (in that the conductivity tensor is nearly diagonal for orthorhombic structure). But if I compare results across different cases, they differ too much under as small as 0.5% lattice constant
change. More details are given below.<br></div><div><br></div>I tried to calculate the conductivity tensor with postw90.x with version 2.1. I tried it on three cases related with slight elongation along a or b directions defining an orthorhombic structure on the original lattice. The resulting conductivity tensor differs by nearly 100% for a 0.5% lattice constant change, which cannot be right. To give you some numbers, the following shows different sigma_x,x scanned under different chemical potentials for different lattice structures, (other components of sigma are suppressed for brevity but the whole sigma matrix does show a diagonal feature expected for an orthorhombic structure.) <br><br></div>For the base structure (a,b,c)<br></div> mu T sigma_x,x<br><div> 7.963542580 2.000000000 0.4228380355E-05<br> 7.963542580 4.000000000 0.6146815602E-01<br> 7.963542580 6.000000000 1.261398051 <br> 7.963542580 8.000000000 5.250207712 <br> 7.963542580 10.00000000 11.71261179 <br><br></div><div>For the elongated structure along a by 0.5%<br> mu T sigma_x,x<br> 7.962242580 2.000000000 0.5201871790E-03<br> 7.962242580 4.000000000 0.6688530829 <br> 7.962242580 6.000000000 6.051666588 <br> 7.962242580 8.000000000 16.35207686 <br> 7.962242580 10.00000000 27.52636769 <br><br></div><div>For the elongated structure along b by 0.5%<br> mu T sigma_x,x<br> 7.951237820 2.000000000 <a href="tel:%28332%29%20903-9665" value="+13329039665" target="_blank">332.9039665</a> <br> 7.951237820 4.000000000 363.9745377 <br> 7.951237820 6.000000000 287.1196636 <br> 7.951237820 8.000000000 <a href="tel:%28228%29%20918-7157" value="+12289187157" target="_blank">228.9187157</a> <br> 7.951237820 10.00000000 188.4869745 <br><br></div><div>Any idea on how to check the calculation? Thanks all very much for your insightful help! <br><br></div><div>Sincerely,<br></div><div>Jun<br></div><div><br></div></div>