Dear Users
I have been doing a vc-relax calculation of a binary compound with AB2
structure that is occupying a triclinic space group with ibrav=14.
I used QE version 6.5.
To keep the ibrav 14 from in the final vc-relax structure, I performed the
vc-relax with celld_dofree='ibrav'
Job has been finished without any warning or error. The final geometry is
mentioned in appendix-A in below to this query.
If I choose the CELL_PARAMETERS and ATOMIC_POSITIONS from above output and
update the case.in file then it gives me ibrav= -13.
I am wondering whether I can choose celldm(1) to celldm(6) and
ATOMIC_POSITIONS from the appendix-A?
Are these celldm's final relaxed cell_parameters?
Please guide me for the above two queries.
Thank you very much
Regards
Rekha
Appendix-A
ibrav = 14
celldm(1) = 7.46334414
celldm(2) = 0.99999702
celldm(3) = 1.79237850
celldm(4) = 0.11014359
celldm(5) = 0.10863152
celldm(6) = 0.24294684
Input lattice vectors:
1.00112336 0.00000000 0.00000000
0.24321903 0.97112641 0.00000000
0.19492754 0.15492538 1.77703235
New lattice vectors in INITIAL alat:
1.00112336 0.00000000 0.00000000
0.24321903 0.97112641 0.00000000
0.19492754 0.15492538 1.77703235
New lattice vectors in NEW alat (for information only):
1.00000000 0.00000000 0.00000000
0.24294611 0.97003671 0.00000000
0.19470881 0.15475153 1.77503835
Discrepancy in bohr = 0.000000 0.000000 0.000000
bfgs converged in 4 scf cycles and 3 bfgs steps
(criteria: energy < 1.0E-04 Ry, force < 1.0E-03Ry/Bohr, cell <
5.0E-01kbar)
End of BFGS Geometry Optimization
Final enthalpy = -68.4522400954 Ry
Begin final coordinates
new unit-cell volume = 715.80761 a.u.^3 ( 106.07174 Ang^3 )
density = 4.43480 g/cm^3
CELL_PARAMETERS (alat= 7.45496956)
1.001123355 0.000000000 0.000000000
0.243219029 0.971126408 0.000000000
0.194927536 0.154925376 1.777032345
ATOMIC_POSITIONS (crystal)
A 0.0000235084 -0.0000109097 0.0000009223
B 0.9616465677 0.4631487680 0.2331366069
B 0.5360299239 0.0391621417 0.7668624708
End final coordinates
Appendix- B
&CONTROL
calculation='vc-relax',
outdir='./tmp',
prefix='scf',
pseudo_dir='.',
verbosity='low',
etot_conv_thr = 0.0001
forc_conv_thr = 0.001
nstep = 400
tstress = .true.
tprnfor = .true.
/
&SYSTEM
ibrav=14,
celldm(1)=7.4549695614d0, celldm(2)=1.0000000000d0,
celldm(3)=1.7936628644d0,
celldm(4)=0.1100812622d0, celldm(5)=0.1085198771d0,
celldm(6)=0.2422605780d0,
nat=3,
ntyp=2,
ecutwfc=50,
ecutrho=500,
/
&ELECTRONS
conv_thr=1d-010,
mixing_beta=0.3d0,
/
&IONS
/
&CELL
cell_dofree='ibrav'
/
ATOMIC_SPECIES
A A.pbe-n-rrkjus_psl.1.0.0.UPF
B B.pbe-n-rrkjus_psl.1.0.0.UPF
ATOMIC_POSITIONS {crystal}
A 0.0000000000d0 0.0000000000d0 0.0000000000d0
B 0.9617000000d0 0.4632000000d0 0.2330000000d0
B 0.5360000000d0 0.0391000000d0 0.7670000000d0
K_POINTS {automatic}
11 11 5 0 0 0
--
Best wishes
Ms. Rekha
Teaching Assistant,
Department of Physics
RK college, Jaipur, India
Mob.: +11 91-95 790 71 697
Email: rekha1997...@gmail.com
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