ABINIT Discussion Forums

Hi all,

I encountered some troubles when I calculated a system of Cu-Ni alloy using the following script.
I tried a simple test for the total energy of Cu3Ni alloy under the different lattice constants. Its running result had not appeared 10 total energies corresponding to a lattice constant, and the calculation stopped after optimized a strucutre or got one total energy.
I don't know where the problem is and how to deal with it.

# Cu3Ni crystal total energy
#Definition of the unit cell
ndtset 10
acell: 3*6.5
acell+ 3*0.1

#ground state calculation
iscf 5
ixc 1

#Defintion of the unit cell
#acell 3*6.8014
optcell 2
ionmov 3
ntime 50
dilatmx 1.5
ecutsm 0.5
occopt 3

rprim
0.0 0.5 0.5
0.5 0.0 0.5
0.5 0.5 0.0

#Definition of the atom types
ntypat 2
znucl 29 28

#Definition of the atoms
natom 4
typat 1 1 1 2
xred
0.0 0.5 0.5
0.5 0.5 0.0
0.5 0.0 0.5
0.0 0.0 0.0

#Gives the number of band, explicitely
nband 50

#Definition of the planewave basis set
ecut 40.0

#Definition of the k-point grid
kptopt 1
ngkpt 12 12 12
nshiftk 4 ,
shiftk
0.5 0.5 0.5
0.5 0.0 0.0
0.0 0.5 0.0
0.0 0.0 0.5

#Definition of the SCF procedure
nstep 60
toldfe 1.0d-8
prtwf 0

Thank you in advance.

Best regard,
Pan

You seem to be changing the size of the unit cell for each ndtset, but then ALSO optimizing the size of the unit cell--why are you doing both? I think for what you want (compute energy as a function of cell volume) you should have optcell 0. Also, are there any forces on any of the atoms? There may not be, due to their site symmetry, in which case there would be no need to use ionmov either. And, for transition metals I would strongly encourage you to use PAW rather than norm-conserving pseudopotentials.

Thank Professor J. Zwanziger very much.
I will have a test as you said.

jzwanzig wrote:
Post by jzwanzig » Mon Apr 16, 2012 11:24 pm