[CPMD-list] Memory allocation

[Jiri Houska]

Hi all CPMD users,
I am now running CPMD on Intel Pentium 4 with 4GB memory. The CPMD version is
3.9.1, compiled with ifc 8.1.0.24 using configuration file BOCHUM-P4 downloaded
from http://www.theochem.ruhr-uni-bochum.de/~axel.kohlmeyer/cpmd-linux. The OS
is Suse9.2 with bigsmp Kernel which should support up to 64 GB memory.

My problem is that the program ends with error message "memory allocation
failed" when it needs more than (approx.) 1 GB of memory. For example, a
WfOptimization (approx. 100 atoms, 10A cubic cell) with cutoff of 45Ry runs well
with peak memory usage (declared at the end of the output file) of 992 MB (~25%
of computer limit), while the same job with cutoff of 50Ry ends with "memory
allocaton failed". Of course, for most of the run the memory usage was much
lower than the peak.

I have checked using another programs that usage of at least 2 GB of memory for
one process is no problem for the computer, so I believe that the problem (lack
of my knowledge) is related to the CPMD program itself. Using "INITIALIZE
WAVEFUNCTION RANDOM" (not "... ATOM") improved the limit slightly (45 -> 50 Ry),
but nothing more.

Does anybody have any idea how to use with CPMD whole memory of the computer (4
GB)? Thanks a lot for any help!

Jiri Houska
PhD student
University of West Bohemia
Czech Republic