[gmx-users] energy minimization on a cluster

[DEEPESH AGARWAL]

Dear all,

My simulated system specifications -

Protein (394 residues) in a cubic box
water layer - 0.9 nm
total no. of atoms - 113000
default density - 1007 g/l
I am running energy minimization using steepest descent technique on a
intel core 2 duo processor. The thing is it is taking whole lot of
time for minimization only, for instance 2700 steps took almost 40
hrs.  Is it normal???
I tried to run it on a cluster by giving a command -

$ grompp_mpi_d -f em1.mdp -c Protein_wb.gro -p Protein.top -np 4 -o input1.tpr

...this command has divided atoms on 4 nodes. But when i ran mdrun it
gave an error, written below....

$ mpirun -np 4  mdrun_mpi_d  -np 4   -s input1.tpr  -o Protein-em_wb
                     -c Protein-min_wb1.gro   -e Protein_ener   -v


Program mdrun_mpi_d, VERSION 3.3.2
Source code file: futil.c, line: 313

File input/output error:
md.log
-------------------------------------------------------

"Player Sleeps With the Fishes" (Ein Bekanntes Spiel Von ID Software)

Halting program mdrun_mpi_d

gcq#236: "Player Sleeps With the Fishes" (Ein Bekanntes Spiel Von ID Software)

[0] MPI Abort by user Aborting program !
[0] Aborting program!
p0_24572:  p4_error: : -1
    p4_error: latest msg from perror: No such file or directory
-----------------------------------------------------------------------------
It seems that [at least] one of the processes that was started with
mpirun did not invoke MPI_INIT before quitting (it is possible that
more than one process did not invoke MPI_INIT -- mpirun was only
notified of the first one, which was on node n0).

mpirun can *only* be used with MPI programs (i.e., programs that
invoke MPI_INIT and MPI_FINALIZE).  You can use the "lamexec" program
to run non-MPI programs over the lambooted nodes.
-----------------------------------------------------------------------------


Could anybody please give any idea what is going wrong, and how to run
energy minimization on a cluster or any other way to reduce the time
drastically. Thanks in advance.

Deepesh