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Dear Abinit users,
   I try to perform a lattice optimization calculation of Ca2MgSi2O7. But It 
can't converge after 30 Broyd/MD steps. My input is as follows. Becauae I am 
a new user of abinit and not familiar with these input variables, I would 
appreciate that anyone can give me some suggestions.
The Pseudopotential I used: Troullier-Martins pseudopotentials for Si and 
O,Hartwigsen-Goedecker-Hutter psp for Ca and Mg.
The abinit version is 4.4.3 for a P6/DOS/Windows computer.
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# Crystalline Ca2MgSi2O7 : computation of the total energy
#
#Optimization of the lattice parameters
optcell 1
ionmov  2
ntime  30
dilatmx 1.05
ecutsm  0.5
toldff = 5.0D-5
tolmxf = 1.0D-4

#Definition of the unit cell
acell 14.79206 14.79206 9.46125          # This is lattice constant
rprim  1.0  0.0  0.0
    0.0  1.0  0.0
    0.0  0.0  1.0

#Definition of the atom types
ntypat 4
znucl 20 12 14 8

#Definition of the atoms
natom 6           # There are six atoms
typat 1 2 3 4 4 4
xred
0.3320 0.1680 0.5050
0      0      0
0.1395 0.3605 0.9334
0.5 0.0 0.1775
0.1409 0.3591 0.2547
0.0816 0.1870 0.7879

ecut 85

#Definition of the k-point grid
kptopt 1          # Option for the automatic generation of k points, taking
               # into account the symmetry

ngkpt 2 2 2
nshiftk 1
shiftk 0.5 0.5 0.5

#Definition of the SCF procedure
nstep 60          # Maximal number of SCF cycles

diemac 12.0
------------------------------

Regards,
Zeming