Failing to relax a 2D structure
Posted: Mon Jan 27, 2020 2:30 pm
Dear experts and users,
I've been trying to relax a 2D Ga structure with no success. Could you please indicate what might be wrong?
The structure has been successfully calculated by me or my colleagues in other DFT packages (QE, VASP).
Thus, I started off with an almost relaxed structure, and I expected it to be fully relaxed in ABINIT within just a few steps.
Indeed, the first step indicated forces of 10^(-5) Ha/bohr, but after a couple of quickly converging relaxation steps the situation got quite bad: all the following steps are not converging well (oscillating residm/vres) and forces are going bad (I terminate the job when forces deteriorate to 10^(-1) Ha/bohr ).
I tried ionmov = 2,3, different versions of Abinit, increasing nband, ecut, ngkpt. Nothing seems to work.
Below I provide an example of my input file:
Thank you very much for the attention.
Best regards, Mikhail
I've been trying to relax a 2D Ga structure with no success. Could you please indicate what might be wrong?
The structure has been successfully calculated by me or my colleagues in other DFT packages (QE, VASP).
Thus, I started off with an almost relaxed structure, and I expected it to be fully relaxed in ABINIT within just a few steps.
Indeed, the first step indicated forces of 10^(-5) Ha/bohr, but after a couple of quickly converging relaxation steps the situation got quite bad: all the following steps are not converging well (oscillating residm/vres) and forces are going bad (I terminate the job when forces deteriorate to 10^(-1) Ha/bohr ).
I tried ionmov = 2,3, different versions of Abinit, increasing nband, ecut, ngkpt. Nothing seems to work.
Below I provide an example of my input file:
Code: Select all
optcell 9
ionmov 2
tolmxf 5.0d-5
strfact 10
ntime 500
dilatmx 1.1
ecutsm 0.5
npulayit 25
nline 6
autoparal 1
acell 1 1 1 angstrom
rprim
+4.7440200000 +0.0000000000 +0.0000000000
+0.0000000000 +4.9204393662 +0.0000000000
+0.0000000000 +0.0000000000 +15.0000000000
ntypat 1
znucl 31
natom 4
typat 1 1 1 1
xangst
+0.0000000000 +1.9081898149 +5.2271844041
+0.0000000000 +4.3684094980 +6.4204537083
+2.3720100000 +0.5520298682 +5.2271844041
+2.3720100000 +3.0122495508 +6.4204537083
ecut 60
nband 40
kptopt 1
ngkpt 32 32 1
nshiftk 1
shiftk 0.0 0.0 0.0
nstep 500
toldfe 1.0d-8
iscf 7
occopt 3
tsmear 0.01
#iprcel 45
Best regards, Mikhail