Dear Sunil Kumar
Check the structure first. I opened your file with xcrysden and even
if it is not totally weird, it is a bit strange (Ni-Y distances of 2.2
A are likely wrong...). Moreover, are you sure you want to use the LDA
(PZ) functional? The electronic structure of a TM oxide will likely be
strongly affected by delocalization errors. Finally, I expect that you
norm-conserving (so no need to specify ecutrho, it has a fixed value
of 4*ecutwfc) mt-fhi pseudopotentials are quite hard, with ecutwfc
maybe as high as 120-140 Ry. In difficult cases (but check the
structure first!) you may lower mixing_beta down to 0.01.
HTH
Giuseppe
Quoting "Dr. SUNIL KUMAR" <[email protected]>:
Dear QE developers and Users.
We are doing DFT simulation of Monoclinic YNiO3 with and without oxygen
vacancy. During the vc-relax and relax relaxation step, energy does not
converge and simulation ends with error msg " convergence NOT achieved
after 200 iterations: stopping" . I have tried many different values of
ecutwfc and mixing_beta but unable to find convergence. Your suggestions
will be highly appreciated.
Following is the script for QE.
Thank you
&CONTROL
calculation = "relax"
prefix = "espresso"
wf_collect = .TRUE.
forc_conv_thr = 1.00000e-03
max_seconds = 1.72800e+05
nstep = 100
pseudo_dir = "/home/pseudopot"
outdir = "./outdir"
wfcdir = "./wfcdir"
/
&SYSTEM
a = 5.17932e+00
b = 5.51529e+00
c = 7.41657e+00
cosac = -1.34914e-03
degauss = 1.00000e-02
ecutrho = 2.25000e+02
ecutwfc = 2.50000e+01
ibrav = -12
nat = 19
nspin = 2
ntyp = 3
occupations = "smearing"
smearing = "gaussian"
starting_magnetization(1) = 2.00000e-01
starting_magnetization(2) = 0.00000e+00
starting_magnetization(3) = 2.00000e-01
/
&ELECTRONS
conv_thr = 1.00000e-06
electron_maxstep = 200
mixing_beta = 4.00000e-01
startingpot = "atomic"
startingwfc = "atomic+random"
/
&IONS
ion_dynamics = "bfgs"
/
&CELL
/
K_POINTS {automatic}
2 2 2 0 0 0
ATOMIC_SPECIES
Ni 58.69340 Ni.pz-mt_fhi.UPF
O 15.99940 O.pz-mt_fhi.UPF
Y 88.90585 Y.pz-mt_fhi.UPF
ATOMIC_POSITIONS {angstrom}
Ni 2.589660 0.000000 0.000000
Ni 0.000000 2.757645 0.000000
Ni -0.005000 0.000000 3.708280
Ni 2.584660 2.757645 3.708280
O 1.796655 1.696862 0.356885
O 1.238791 4.384435 0.375842
O 0.756099 2.606316 1.812340
O 4.418221 5.363961 1.895940
O 3.935529 1.626790 3.332439
O 3.377665 4.454507 3.351395
O 1.233790 3.888500 4.084122
O 0.751099 0.151329 5.520620
O 4.413221 2.908974 5.604220
O 3.930529 1.130855 7.040719
O 3.372665 3.818428 7.059675
Y 3.782084 3.157134 1.851618
Y 1.392236 0.399489 1.856662
Y 3.777084 5.115801 5.559899
Y 1.387236 2.358156 5.564942
Dr. Sunil Kumar
Ph.D (Chemical Engg. IIT Delhi)
M.Tech (Chemical Engg. IIT Delhi)
B.Tech (Chemical Engg. IET-CSJMU Kanpur)
Senior Scientist (E1) and Assistant Professor
CSIR-National Metallurgical Laboratory Jamshedpur-831007
http://www.nmlindia.org/
https://scholar.google.co.in/citations?user=OchYqugAAAAJ&hl=en&oi=sra
GIUSEPPE MATTIOLI
CNR - ISTITUTO DI STRUTTURA DELLA MATERIA
Via Salaria Km 29,300 - C.P. 10
I-00015 - Monterotondo Scalo (RM)
Mob (*preferred*) +39 373 7305625
Tel + 39 06 90672342 - Fax +39 06 90672316
E-mail: <[email protected]>
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