[QE-users] Huge difference in the total and Fermi energies in vc-relax, scf and dos

Sat Dec 17 19:16:37 CET 2022

Dear all,
Initially I took the material from https://materialsproject.org/materials/mp-1172828?chemsys=W-O then did the vc-relax and the structure has been distorted. I've attached structure after relaxation as wo3.png.
The input file is as follows,
&CONTROL
calculation = 'vc-relax'
nstep = 100
outdir = './out'
prefix = 'wo'
pseudo_dir = './upf'
/
&SYSTEM
degauss = 0.002
ecutwfc = 50
ibrav = 0
nat = 32
ntyp = 2
occupations = 'smearing'
lda_plus_u = .TRUE.
Hubbard_U(1) = 6.2
/
&ELECTRONS
electron_maxstep = 100
mixing_beta = 0.5
scf_must_converge = .FALSE.
/
&IONS
/
&CELL
/
ATOMIC_SPECIES
W 183.85 W.pbe-spfn-kjpaw_psl.1.0.0.UPF
O 15.9994 O.pbe-nl-kjpaw_psl.1.0.0.UPF
K_POINTS gamma
CELL_PARAMETERS {angstrom}
7.6020550000 0.0000000000 0.0000000000
0.0000000000 7.7001040000 0.0000000000
0.0000000000 0.0000000000 7.7471430000
ATOMIC_POSITIONS {angstrom}
W 5.708846824855 0.13598383664 5.936782876617
W 5.694235675145 0.13598383664 2.063211376617
W 1.8932081751450012 7.564120163359999 1.8103601233830007
W 1.8932081751450007 3.71406816336 5.936782876617
W 5.708846824855001 3.9860358366399997 1.8103601233830007
W 5.694235675145001 3.9860358366399997 5.6839316233830015
W 1.907819324855001 7.564120163359999 5.6839316233830015
W 1.9078193248550006 3.71406816336 2.063211376617
O 5.479074712480001 5.833752792479999 5.787743339583001
O 3.798070300605 0.222694707784 5.61939017505
O 2.1229802875200003 1.8663512075200015 1.9593996604170003
O 5.92400778752 1.9837007924799974 5.832971160417001
O 5.5098402290649995 0.074590907448 0.0293306833980004
O 7.599097800605001 7.477409292216 6.0013243249500015
O 0.002957199395 0.222694707784 1.7458186750499993
O 5.924007787520001 5.833752792479999 1.9141718395830016
O 0.0029571993950006 4.072746707784 6.001324324950001
O 3.7980703006050005 4.072746707784 2.1277528249500013
O 1.7088127290650013 7.625513092552 3.844240816602001
O 7.599097800605001 3.6273572922160002 1.7458186750500002
O 3.8039846993950013 7.477409292216 2.1277528249500017
O 1.7088127290650008 3.775461092552 3.902902183398
O 5.47907471248 1.9837007924799974 1.9593996604170005
O 2.0922147709350005 3.775461092552 0.0293306833980004
O 3.8039846993950004 3.6273572922160002 5.61939017505
O 5.509840229065 3.924642907448 7.717812316602001
O 1.6780472124800008 5.716403207520001 1.9141718395830014
O 2.0922147709350014 7.625513092552 7.717812316602001
O 5.8932422709350005 0.074590907448 3.9029021833980004
O 2.122980287520001 5.716403207520001 5.787743339583001
O 5.893242270935001 3.924642907448 3.844240816602001
O 1.67804721248 1.8663512075200015 5.832971160417

The final atomic positions in the output is as follows,
CELL_PARAMETERS {angstrom}
7.7283550000 0.0000000000 0.0000000000
0.0000000000 7.7668290000 0.00000000000.0000000000 0.0000000000 7.1925630000

ATOMIC_POSITIONS {angstrom}
W 5.61005926463 0.248103585576 5.383712523693
W 5.982465507015 0.248103585576 1.787431023693
W 2.11829573537 7.518725414424001 1.8088504763070001
W 2.11829573537 3.6353109144240006 5.383712523693
W 5.61005926463 4.131518085576 1.8088504763070001
W 5.982465507015 4.131518085576 5.40513916887
W 1.7458817646299998 7.518725414424001 5.40513916887
W 1.7458817646299998 3.6353109144240006 1.787431023693
O 5.318398875284999 5.7449059400880005 5.321151610719
O 3.9082754936299997 0.5044633103789999 5.111790486915
O 2.40994839636 2.021923059912 1.8714185818439997
O 6.274125896359999 1.861491440088 5.467700081844
O 5.55687272552 7.5224845596600005 7.187787138168
O 0.0440979936299999 7.262365689621 5.677054013085
O 7.684257006369999 0.5044633103789999 1.515508986915
O 6.274125896359999 5.7449059400880005 1.7248701107189999
O 7.684257006369999 4.387877810379 5.677054013085
O 3.9082754936299997 4.387877810379 2.0807725130850003
O 1.6926952255199998 0.2443444403400004 3.601057361832
O 0.0440979936299999 3.3789511896210005 1.515508986915
O 3.82007950637 7.262365689621 2.0807725130850003
O 1.6926952255199998 4.127758940340001 3.591505638168
O 5.318398875284999 1.861491440088 1.8714185818439997
O 2.1714822744799998 4.127758940340001 7.187787138168
O 3.82007950637 3.3789511896210005 5.111790486915
O 5.55687272552 3.6390700596600003 0.0047830543949994
O 1.454221375285 5.905337559912001 1.7248701107189999
O 2.1714822744799998 0.2443444403400004 0.0047830543949994
O 6.03565977448 7.5224845596600005 3.591505638168
O 2.40994839636 5.905337559912001 5.321151610719
O 6.03565977448 3.6390700596600003 3.601057361832
O 1.454221375285 2.021923059912 5.467700081844

But the same material is getting relaxed properly in vasp and its input can be procured from the same link.
I've tried with the pbesol and pbe_uspp pseudo potential files where many cbands were not converged and the convergence was not achieved.
When I tried with the pbe_paw pseudo potentials obtained from the following link http://pseudopotentials.quantum-espresso.org/legacy_tables the vc-relax was perfect. But there is a huge difference in the total energy and Fermi energy. In this calculation the changes in the input are pseudo potentials and k-points 5 5 5 0 0 0. The energies are as follows,

- vc-relax : Total energy = -7089.53 and Fermi energy = -6.324
- scf : Total energy = -9863.47 and Fermi energy = -11.848
- nscf_dos : Total energy = -11567.89 and Fermi energy = -20.678

I tried playing with the ecutwfc and Hubbard parameter. I've also checked with the cg diagonalization. Please guide me in this calculation and let me know my mistake in the input file. All the calculations were done using QE version 7.
Thanking you,
Greeshma R
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