Si relaxation
Relaxation of the internal coordinates of a perturbed cd Si structure.
Break of symmetry in standard diamond structure: change z position from 0.125 to 0.130.
Converting to the format of QE.
calculation = ‘vc-relax’: allow cell to be relaxed.
calculation = ‘relax’: only relax the atomic positions。
mpirun $PW_EXEC -nk 4 < input > ./report
rm pwscf.wfc*
rm pwscf.save/wfc*
check the energy convergence:
grep "! total energy" report
awk '/Begin final coordinates/,/End final coordinates/{print $0}' report
POSCAR
Si
1.0
3.8401000500 0.0000000000 0.0000000000
1.9200500250 3.3256241964 0.0000000000
1.9200500250 1.1085413988 3.1354285612
Si
2
Direct
0.000000000 0.000000000 0.000000000
0.250000000 0.250000000 0.250000000
Converting to the format of QE.
structure
CELL_PARAMETERS angstrom
0.0000000000000000 2.5000000000000000 2.5000000000000000
2.5000000000000000 0.0000000000000000 2.5000000000000000
2.5000000000000000 2.5000000000000000 0.0000000000000000
ATOMIC_SPECIES
Si 28.086 Si.UPF
ATOMIC_POSITIONS crystal
Si -0.1250000000000000 -0.1250000000000000 -0.1250000000000000
Si 0.1250000000000000 0.1250000000000000 0.1300000000000000
input
&CONTROL
calculation = "vc-relax",
pseudo_dir = '/public/home/users/shu003/pseudo_QE',
prefix = 'pwscf',
outdir = './tmp',
verbosity='high', tprnfor=.true., tstress=.true., forc_conv_thr=1.0d-5,
nstep=50
/
&SYSTEM
ibrav = 0,
ntyp = 1,
nat = 2,
ecutwfc = 30.D0,
occupations = "smearing",
smearing = "gaussian",
degauss = 0.0005
/
&ELECTRONS
electron_maxstep = 30
conv_thr = 1.D-6,
mixing_mode = 'plain',
mixing_beta = 0.8d0,
diagonalization = 'david'
/
&IONS
ion_dynamics = 'bfgs',
/
&CELL
press_conv_thr=0.1,cell_dofree='all'
/
CELL_PARAMETERS angstrom
0.0000000000000000 2.5000000000000000 2.5000000000000000
2.5000000000000000 0.0000000000000000 2.5000000000000000
2.5000000000000000 2.5000000000000000 0.0000000000000000
ATOMIC_SPECIES
Si 28.086 Si.UPF
ATOMIC_POSITIONS crystal
Si -0.1250000000000000 -0.1250000000000000 -0.1250000000000000
Si 0.1250000000000000 0.1250000000000000 0.1300000000000000
K_POINTS {automatic}
6 6 6 0 0 0
rm pwscf.wfc*
rm pwscf.save/wfc*
check the energy convergence:
grep "! total energy" report
awk '/Begin final coordinates/,/End final coordinates/{print $0}' report