I'm studying a compound $\ce{VSe_2}$ using the DFT package Quantum ESPRESSO (QE). The following is the input file.
&CONTROL
calculation = 'scf'
outdir = './outdir'
verbosity = 'high'
tprnfor = .true.
tstress = .true.
pseudo_dir = '.'
/
&SYSTEM
ibrav = 0
A = 3.35381
nat = 3
ntyp = 2
ecutwfc = 55
ecutrho = 650
starting_magnetization(1) = 1
starting_magnetization(2) = 0
lspinorb = .true.
noncolin = .true.
occupations = 'smearing'
smearing = 'mv'
degauss = 0.005d0
/
&ELECTRONS
conv_thr = 1e-8
mixing_beta = 0.7d0
/
CELL_PARAMETERS {alat}
1.000000000000000 0.000000000000000 0.000000000000000
-0.500000000000000 0.866025403784439 0.000000000000000
0.000000000000000 0.000000000000000 2.087308375869810
ATOMIC_SPECIES
V 50.94150 V.rel-pbe-spnl-kjpaw_psl.1.0.0.UPF
Se 78.96000 Se.rel-pbe-dn-kjpaw_psl.1.0.0.UPF
ATOMIC_POSITIONS {crystal}
Se 0.666666666666667 0.333333333333333 0.774935000000000
Se 0.333333333333333 0.666666666666667 0.225065000000000
V 0.000000000000000 0.000000000000000 0.000000000000000
K_POINTS {automatic}
6 6 6 0 0 0
When I'm using a threshold of $10^{-8}$, the SCF loop doesn't converge after 100 iterations. Is it okay to use a lower threshold of $10^{-4}$ so as to aid convergence?
SCF output:
estimated scf accuracy < 0.00015001 Ry
estimated scf accuracy < 0.00017012 Ry
estimated scf accuracy < 0.00023876 Ry
estimated scf accuracy < 0.00015530 Ry
estimated scf accuracy < 0.00010229 Ry
estimated scf accuracy < 0.00030521 Ry
estimated scf accuracy < 0.00038586 Ry
estimated scf accuracy < 0.00035244 Ry
estimated scf accuracy < 0.00018834 Ry
estimated scf accuracy < 0.00026472 Ry
estimated scf accuracy < 0.00026759 Ry
estimated scf accuracy < 0.00035791 Ry
estimated scf accuracy < 0.00014860 Ry
estimated scf accuracy < 0.00023776 Ry
estimated scf accuracy < 0.00031980 Ry
estimated scf accuracy < 0.00023777 Ry
estimated scf accuracy < 0.00029549 Ry
estimated scf accuracy < 0.00031407 Ry
estimated scf accuracy < 0.00009668 Ry
estimated scf accuracy < 0.00019794 Ry