GROMACS

To load the module for the default version of GROMACS, which initializes your environment for the GROMACS application, use  module load gromacs. To select a particular software version, use  module load gromacs/version. For example, use  module load gromacs/5.1 to load GROMACS version 5.1; and use module help gromacs/5.1 to view details, such as, compiler prerequisites, additional modules required for specific executables, the suffixes of executables, etc.

The syntax of the GROMACS executable(s) changed in version 5. To execute a serial GROMACS versions 4 program interactively, simply run it on the command line, e.g.:

pdb2gmx

To execute a serial GROMACS versions 5 program interactively, simply run it on the command line, e.g.:

gmx pdb2gmx

Note that some serial executables are enabled for single node parallelism via OpenMP.  Parallel multinode GROMACS versions 4 programs should be run in a batch environment with mpiexec, e.g.:

mpiexec mdrun_mpi_d

Parallel multinode GROMACS versions 5 programs should be run in a batch environment with mpiexec, e.g.:

mpiexec gmx_mpi_d mdrun

Note that '_mpi' indicates a parallel executable and '_d' indicates a program built with double precision ('_gpu' denotes a GPU executable built with CUDA).  See the module help output for specific versions for more details on executable naming conventions.

When you log into Oakley you are actually connected to a login node. To  access the compute nodes, you must submit a job to the batch system for execution. Batch jobs can request multiple nodes/cores and compute time up to the limits of the OSC systems. Refer to Queues and Reservations and Batch Limit Rules for more info. 

Interactive Batch Session

For an interactive batch session on Oakley, one can run the following command:

qsub -I -l nodes=1:ppn=12 -l walltime=1:00:00

which gives you 12 cores (-l nodes=1:ppn=12) with 1 hour (-l walltime=1:00:00). You may adjust the numbers per your need.

Non-interactive Batch Job (Parallel Run)

A batch script can be created and submitted for a serial or parallel run. You can create the batch script using any text editor you like in a working directory on the system of your choice. Sample batch scripts and input files are available here:

~srb/workshops/compchem/gromacs/

This simple batch script demonstrates some important points:

# GROMACS Tutorial for Solvation Study of Spider Toxin Peptide
# see fwspider_tutor.pdf
#PBS -N fwsinvacuo.oakley
#PBS -l nodes=2:ppn=12
module unload intel
module load intel/12.1.4.319
module load mvapich2/1.7
module load gromacs/4.6.3
# PBS_O_WORKDIR refers to the directory from which the job was submitted.
cd $PBS_O_WORKDIR
pbsdcp -p 1OMB.pdb em.mdp $TMPDIR
# Use TMPDIR for best performance.
cd $TMPDIR
pdb2gmx -ignh -ff gromos43a1 -f 1OMB.pdb -o fws.gro -p fws.top -water none
editconf -f fws.gro -d 0.7
editconf -f out.gro -o fws_ctr.gro -center 2.0715 1.6745 1.914
grompp -f em.mdp -c fws_ctr.gro -p fws.top -o fws_em.tpr
mpiexec mdrun_mpi -s fws_em.tpr -o fws_em.trr -c fws_ctr.gro -g em.log -e em.edr
cat em.log
cp -p * $PBS_O_WORKDIR/

To load the module for the default version of GROMACS, which initializes your environment for the GROMACS application, use module load gromacs. To select a particular software version, use module load gromacs/version. For example, use module load gromacs/5.1.2 to load GROMACS version 5.1.2; and use module help gromacs/5.1.2 to view details, such as, compiler prerequisites, additional modules required for specific executables, the suffixes of executables, etc.; some versions require specific prerequisite modules, and such details may be obtained with the command   module spider gromacs/version.

To execute a serial GROMACS versions 5 program interactively, simply run it on the command line, e.g.:

gmx pdb2gmx

Parallel multinode GROMACS versions 5 programs should be run in a batch environment with mpiexec, e.g.:

mpiexec gmx_mpi_d mdrun

Note that '_mpi' indicates a parallel executable and '_d' indicates a program built with double precision ('_gpu' denotes a GPU executable built with CUDA).  See the module help output for specific versions for more details on executable naming conventions.

When you log into Owens you are actually connected to a login node. To  access the compute nodes, you must submit a job to the batch system for execution. Batch jobs can request multiple nodes/cores and compute time up to the limits of the OSC systems. Refer to Queues and Reservations and Batch Limit Rules for more info. 

Interactive Batch Session

For an interactive batch session on Owens, one can run the following command:

qsub -I -l nodes=1:ppn=28 -l walltime=1:00:00

which gives you 28 cores (-l nodes=1:ppn=28) with 1 hour (-l walltime=1:00:00). You may adjust the numbers per your need.

Non-interactive Batch Job (Parallel Run)

A batch script can be created and submitted for a serial, cuda (GPU), or parallel run. You can create the batch script using any text editor in a working directory on the system of your choice. Sample batch scripts and input files for all types of hardware resources are available here:

~srb/workshops/compchem/gromacs/

This simple batch script demonstrates some important points:

# GROMACS Tutorial for Solvation Study of Spider Toxin Peptide
# see fwspider_tutor.pdf
#PBS -N fwsinvacuo.owens
#PBS -l nodes=2:ppn=28
module load gromacs
# PBS_O_WORKDIR refers to the directory from which the job was submitted.
cd $PBS_O_WORKDIR
pbsdcp -p 1OMB.pdb em.mdp $TMPDIR
# Use TMPDIR for best performance.
cd $TMPDIR
pdb2gmx -ignh -ff gromos43a1 -f 1OMB.pdb -o fws.gro -p fws.top -water none
editconf -f fws.gro -d 0.7
editconf -f out.gro -o fws_ctr.gro -center 2.0715 1.6745 1.914
grompp -f em.mdp -c fws_ctr.gro -p fws.top -o fws_em.tpr
mpiexec gmx_mpi mdrun -s fws_em.tpr -o fws_em.trr -c fws_ctr.gro -g em.log -e em.edr
cat em.log
cp -p * $PBS_O_WORKDIR/