[Pw_forum] convergence w.r.t ecutwfc
Amin Torabi
mtorabi at uwo.ca
Mon Aug 29 00:34:53 CEST 2011
Dear QE-users,
Will you please take a look at my input file and convergence table below:
I am using PBE USPP for both hydrogen and boron, but calculating energies
using PBEsol. (ecutrho is set to 12* ecutwfc.)
My question is:
1. Does it look normal? I was expecting to see 1mRy accuracy at lower
ecutwfc values.
2. I didn't use "occupations" or "smearing" and I didn't get any error in
output files. Do they affect the convergence?
3. I want to do vc-relax calculation at high pressure. Based on my table,
what ecutwfc do you suggest?
Thanks in advance.
ecutwfc energy
30 -38.28149597
35 -38.28437812
40 -38.28554856
45 -38.28658930
50 -38.28772083
55 -38.28883141
60 -38.28989311
65 -38.29086868
70 -38.29167889
75 -38.29227767
80 -38.29267847
85 -38.29291696
90 -38.29302834
95 -38.29305836
100 -38.29305908
105 -38.29307545
110 -38.29313486
115 -38.29324982
&control
pseudo_dir = **
outdir = **
prefix = '$a'
tstress = .true
tprnfor = .true
verbosity = 'low'
/
&SYSTEM
ibrav = 12
celldm(1) = 8.31479435
celldm(2) = 1.3
celldm(3) = 1.4772727273
celldm(4) = -0.260504508642648
nat = 16
ntyp = 2
ecutwfc = $a
ecutrho = `expr 12 \* $a`
input_dft = 'pbesol'
/
&ELECTRONS
/
ATOMIC_SPECIES
B 10.811 B.pbe-n-van_ak.UPF
H 1.00794 H.pbe-van_ak.UPF
ATOMIC_POSITIONS crystal
B 0.002 0.146 0.042
H -0.194 0.166 0.140
H 0.196 0.294 -0.005
H 0.104 -0.019 0.112
B -0.002 -0.146 -0.042
H 0.194 -0.166 -0.140
H -0.196 -0.294 0.005
H -0.104 0.019 -0.112
B 0.498 0.354 0.542
H 0.694 0.334 0.640
H 0.304 0.206 0.495
H 0.396 0.519 0.612
B 0.502 0.646 0.458
H 0.306 0.666 0.360
H 0.696 0.794 0.505
H 0.604 0.481 0.388
K_POINTS automatic
8 8 8 0 0 0
--
Amin Torabi
Ph.D. Student
Chemistry Department
The University *of* Western Ontario
London, On Canada, N6A 5B7
Phone: 519-661-2111 Ext: 87871
****************************************
--
Amin Torabi
Ph.D. Student
Chemistry Department
The University *of* Western Ontario
London, On Canada, N6A 5B7
Phone: 519-661-2111 Ext: 87871
****************************************
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