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[Stephen.Hocker@mpa.uni-stuttgart.de]

Dear Abinit users,

I'm trying to calculate the elastic constants of B2 NiAl using the serial
version of Abinit 5.4.4, unfortunately I didn't obtain any results yet. Some
values for the parameters in my infile must be wrong, but I have no idea
which ones I should change.
The calculation starting from an input file like the one for Al which is 
given in the elastic tutorial stopped with the message:
kpgsph : BUG -
  The variables ikg, mkmem, and mpw  must satisfy ikg<=(mkmem-1)*mpw,
  while the arguments of the routine are
  ikg =    3060, mkmem =      20, mpw =     159
  Probable cause: Known error in invars1 for parallel spin-polarized case.
  Temporary solution: Change the number of parallel processes.
  Action : contact ABINIT group.

Therefore I decided to determine the elastic constants by calculation of the
energies of strained samples. In these calculations the total energy should 
increase parabolically with increasing strain. But it doesn't. Depending on 
the parameters it usually increases somehow, but the curve is never a 
parabola. In some cases it even decreases a little.  
These are the parameters I already tried:
ecut (280...480 eV)
ngkpt (2 2 2...10 10 10)
nband/fband 65/0.0d0 
occopt 3...4
tsmear 0.03...0.07
I tried with different pseudopotentials (Troullier-Martins) as well, namely
13al.pspnc, 28ni.pspnc / 13-Al.LDA.fhi, 28-Ni.LDA.fhi,  13-Al.GGA.fhi,
28-Ni.GGA.fhi.

What else could be wrong? Thanks for any help.
Best regards,
Stephen

This is one of my infiles: 
acell 5.7970482729504687 5.767560060000 5.767560060000 angstrom
ecut 480 eV
ionmov 0 
ixc 1 
kptopt 1 
natom 16
ngkpt 10 10 10 
nstep 15 
ntypat 2 
nband 65
occopt 4 
tsmear 0.03
toldfe 0.005 eV
chkprim 0
znucl 13 28
typat 
1
1
1
1
1
1
1
1
2
2
2
2
2
2
2
2
xangst 0.000000 0.000000 0.000000
0.000000 0.000000 2.883780
0.000000 2.883780 0.000000
0.000000 2.883780 2.883780
2.898524 0.000000 0.000000
2.898524 0.000000 2.883780
2.898524 2.883780 0.000000
2.898524 2.883780 2.883780
1.449262 1.441890 1.441890
1.449262 1.441890 4.325670
1.449262 4.325670 1.441890
1.449262 4.325670 4.325670
4.347786 1.441890 1.441890
4.347786 1.441890 4.325670
4.347786 4.325670 1.441890
4.347786 4.325670 4.325670