Dear all,
I have carried out cpmd calculation with cp.x on a Ge diamond-structured 2x1x1
supercell. However, it seems like that it is impossible to reach the electronic
ground state. It is weird that the Scf total energy is positive and much large
as listed following.
nfi ekinc temph tempp etot enthal econs
econt vnhh xnhh0 vnhp xnhp0
1 ******** 0.0 0.0 17152.83801 17152.83801 17152.83801
29797.11310 0.0000 0.0000 0.0000 0.0000
2 ******** 0.0 0.0 7970.13546 7970.13546 7970.13546
34498.19739 0.0000 0.0000 0.0000 0.0000
3 ******** 0.0 0.0 28546.42723 28546.42723 28546.42723
58500.61459 0.0000 0.0000 0.0000 0.0000
4 ******** 0.0 0.0 95316.89267 95316.89267 95316.89267
128235.67301 0.0000 0.0000 0.0000 0.0000
5 ******** 0.0 0.0 68985.53624 68985.53624 68985.
I have tried to tune emass, dt, cut-offs, however, it doesn't work.
I use the pp Ge.pbe-dn-rrkjus_psl.0.2.2.UPF from http://www.quantum-espesso.org
Any idea about what might be causing this problem? My input file is appended.
&CONTROL
title = 'cd_211 ',
calculation='cp',
restart_mode='from_scratch',
ndr = 51,
ndw = 51,
nstep=500,
iprint = 10,
isave = 1000,
tstress = .TRUE.,
tprnfor = .TRUE.,
dt = 3.0d0,
etot_conv_thr = 1.d-9,
! forc_conv_thr = 1.d-3
ekin_conv_thr = 1.d-4,
prefix = 'bct_Ge'
pseudo_dir = '/home/Ge/cpmd/',
outdir='/home/Ge/cpmd/',
! disk_io='high'
/
&SYSTEM
ibrav = 14,
celldm(1) = 21.382,
celldm(2)= 0.5,
celldm(3)= 0.5,
celldm(4)=0,
celldm(5)=0,
celldm(6)=0,
nat= 16, ntyp= 1,
ecutwfc = 40.0,
ecutrho = 400.0,
nr1b = 15, nr2b = 15, nr3b = 15,
/
&ELECTRONS
emass = 300.d0,
emass_cutoff = 2.5d0,
orthogonalization = 'Gram-Schmidt',
electron_dynamics = 'sd',
conv_thr = 1.0d-6,
! electron_damping = 0.2,
electron_velocities = 'zero',
/
&IONS
ion_dynamics = 'none',
! ion_velocities = 'zero',
! ion_damping = 0.1,
/
ATOMIC_SPECIES
Ge 72.64 Ge.pbe-dn-rrkjus_psl.0.2.2.UPF
ATOMIC_POSITIONS crystal
Ge -0.00000 0.00000 0.00000
Ge -0.00000 0.50000 0.50000
Ge 0.25000 0.00000 0.50000
Ge 0.25000 0.50000 0.00000
Ge 0.37500 0.25000 0.75000
Ge 0.12500 0.25000 0.25000
Ge 0.12500 0.75000 0.75000
Ge 0.37500 0.75000 0.25000
Ge 0.50000 0.00000 0.00000
Ge 0.50000 0.50000 0.50000
Ge 0.75000 0.00000 0.50000
Ge 0.75000 0.50000 0.00000
Ge 0.87500 0.25000 0.75000
Ge 0.62500 0.25000 0.25000
Ge 0.62500 0.75000 0.75000
Ge 0.87500 0.75000 0.25000
Thanks,
Dong
--
Juncai Dong
PhD. Candidate
Beijing Synchrotron Radiation Facility (BSRF)
Institute of High Energy Physics
Chinese Academy of Sciences
P.R.China
