Dear Mohamed,
This probably does not resolve your problem, but still: Did you check
the convergence of the properties with respect to the cut-off energy,
'ecutwfc'? We traditionally used values of 80-100 Ry, but I must confess
that I do not know exactly this potential. Also I would converge the
final electronic structure a bit better than the default value of 10^-6
('conv_thr'). Are these relaxed atomic positions?
Greetings,
apsi
-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-
Ari Paavo Seitsonen / [email protected] / http://www.iki.fi/~apsi/
Ecole Normale Supérieure (ENS), Département de Chimie, Paris
Mobile (F) : +33 789 37 24 25 (CH) : +41 79 71 90 935
On Sun, 6 Dec 2015, Mohamed Elshazly wrote:
Hello everyone,
I'm trying to reproduce the dielectric constant of alpha-alumina using
PHonon. However, I'm getting values close to third of the actual dielectric
constant and cannot figure out why. I also had the same issue with
Columbite-(Mg), so it's not a particular problem with that material system.
Here are my SCF and PH input files:
&control
calculation='scf',
outdir='./out',
prefix='alo',
pseudo_dir='.',
tstress=.true.,
tprnfor=.true.,
forc_conv_thr=1.0D-8,
etot_conv_thr=1.0D-6,
/
&system
ibrav=0,
celldm(1)=9.69051561,
nat=10,
ntyp=2,
ecutwfc=50,
/
&electrons
diago_full_acc=.true.,
/
&ions
/
ATOMIC_SPECIES
O 15.9994 O.pbe-mt.UPF
Al 26.981539 Al.pbe-mt_fhi
CELL_PARAMETERS alat
0.444822702 -0.256818507 0.805845773
-0.000000000 0.513637014 0.805845773
-0.444822702 -0.256818507 0.805845773
ATOMIC_POSITIONS crystal
O 0.058814216 0.749985721 0.441239527
O 0.250014279 0.558760473 0.941185784
O 0.441239527 0.058814216 0.749985721
O 0.558760473 0.941185784 0.250014279
O 0.749985721 0.441239527 0.058814216
O 0.941185784 0.250014279 0.558760473
Al 0.148217545 0.148217545 0.148217545
Al 0.351772827 0.351772827 0.351772827
Al 0.648227173 0.648227173 0.648227173
Al 0.851782455 0.851782455 0.851782455
K_POINTS automatic
16 16 16 0 0 0
PH:
alo_dielectric
&INPUTPH
tr2_ph=1e-15,
outdir='./out',
prefix='alo',
epsil=.true.,
/
0 0 0
Any help would be greatly appreciated.
Mohamed Elshazly
Edward S. Rogers Department of Electrical and Computer Engineering
University of Toronto
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