Dear pwscf user,
Recently, I calculated Bilayer graphene with vdw correction. In version of
4.3, the parameter of London can be set to 'true'
and then add vdw correction to Exc. In version of 5.1, more options can do it,
such as, 'grimmer-d2', 'dft-d'. However, many tests have been performed but I
cannot get the layer-distance (3.34 angstrom in experiment). I uesd GGA-PBE and
LDA-PZ with vdw, recepetively. The final results shows small distance (3.0
angstrom). I donnot know why leads to the small distance. So, I still tested
the Ecut (30Ry-60Ry0) and vaccum (10-20 angstrom), but the problem was the
same.
The input file is,
&CONTROL
calculation = 'relax' ,
outdir ='./tmp' ,
restart_mode = 'from_scratch' ,
pseudo_dir ='/home/plgong/pseudo',
etot_conv_thr = 1.0e-4 ,
forc_conv_thr = 1.0e-3 ,
prefix='graphene',
/
&SYSTEM
ibrav = 4,
a =2.46
c =10.0
nat = 4,
ntyp = 1,
ecutwfc = 30.D0 ,
ecutrho = 240.0 ,
vdw_corr='grimme-d2'
tot_charge = 0.00,
occupations = 'smearing' ,
degauss = 0.02 ,
smearing='mv'
/
&ELECTRONS
conv_thr = 1.D-7 ,
mixing_beta=0.3
mixing_mode='local-TF'
electron_maxstep=300
/
&IONS
ion_dynamics = 'bfgs' ,
/
ATOMIC_SPECIES
C 12.00000 C.pz-rrkjus.UPF
ATOMIC_POSITIONS {crystal}
C 0.000000 0.000000 0.500000
C 0.333333 0.666667 0.500000
C 0.000000 0.000000 0.834000
C 0.666667 0.333333 0.834000
K_POINTS {automatic}
30 30 1 0 0 0
Can anyone help me to solve it?
P. L. Gong
ISSP CAS, HeFei, China
--
====================================================
Addr: Institute of Solid State Physics, Chinese Academy of
Sciences, Hefei, Anhui 230031, China
Tel: +86-551-65591591(office), 18756086113(cell phone)
Email: plg...@theory.issp.ac.cn
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