Hi everyone,
I am trying to obtain a converged SCF calculation (using Quantum ESPRESSO,
version 7.0) for the medium-entropy oxide (CoCuMgZn)0.25 O. This material
crystalizes in the rocksalt structure. I am using a 64-atom supercell. I have
attached my input file at the end of this message.
My problem is: after 50 iterations, my calculations show no trend towards
convergence (ie. the 'estimated scf accuracies' in the pw.x output file
stabilize around 0.5 Ry). I have made the following adjustments in an effort to
achieve better convergence:
* using degauss values of 0.001, 0.01, 0.02
* using a 6 x 6 x 6 K-mesh
* using mixing_beta of 0.05, 0.1, 0.2
* using ecutwfc of 60, 70, 100 (each with 10x ecutrho)
* using PBEsol, PBE pseudopotentials
My question is: do you think it is possible to achieve a converged SCF
calculation using QE? If it is, what might an appropriate value of conv_thr be,
and could you suggest other changes to my input file I could try?
Thank you for your time,
Connor Wilson
Brock University
Department of Mathematics and Science
1812 Sir Issac Brock Way, St. Catharines, ON, CAN, L2S 3A1
######################## pw.x input ###########################
&CONTROL
calculation = 'scf',
prefix = 'MEO',
tstress = .true.,
tprnfor = .true.,
restart_mode = 'from_scratch',
outdir = '/home/cw279/projects/def-crandles/cw279/MEO/222c/alat'
pseudo_dir = '/home/cw279/pseudo',
/
&SYSTEM
ibrav = 1,
celldm(1) = 15.1,
nat = 64,
ntyp = 5,
ecutwfc = 100,
ecutrho = 1000,
occupations = 'smearing',
smearing = 'mv',
degauss = 0.01,
/
&ELECTRONS
electron_maxstep = 50,
mixing_beta = 0.1,
conv_thr = 1.0d-6,
mixing_mode = 'local-TF',
mixing_ndim = 10,
/
ATOMIC_SPECIES
Mg 24.305 Mg.pbe-spnl-kjpaw_psl.1.0.0.UPF
O 15.9994 O.pbe-n-kjpaw_psl.1.0.0.UPF
Zn 65.380 Zn.pbe-dnl-kjpaw_psl.1.0.0.UPF
Ni 58.6934 Ni.pbe-spn-kjpaw_psl.1.0.0.UPF
Co 58.9332 Co.pbe-spn-kjpaw_psl.0.3.1.UPF
K_POINTS {automatic}
4 4 4 0 0 0
ATOMIC_POSITIONS {crystal}
........
_______________________________________________
The Quantum ESPRESSO community stands by the Ukrainian
people and expresses its concerns about the devastating
effects that the Russian military offensive has on their
country and on the free and peaceful scientific, cultural,
and economic cooperation amongst peoples
_______________________________________________
Quantum ESPRESSO is supported by MaX (www.max-centre.eu)
users mailing list [email protected]
https://lists.quantum-espresso.org/mailman/listinfo/users
