# Job submission on HPC using pbs script **URL:** \ **Category:** User discussions\ **Tags:** mdrun, mdrun-parallelization\ **Created:** [November 2, 2023, 5:03am UTC](https://gromacs.bioexcel.eu/t/job-submission-on-hpc-using-pbs-script/7532 "2023-11-02T05:03:14Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![Sachin\_Rajpoot](https://avatars.discourse-cdn.com/v4/letter/s/8e7dd6/32.png) [@Sachin\_Rajpoot](https://gromacs.bioexcel.eu/u/Sachin_Rajpoot)\ **Post date:** [November 2, 2023, 5:03am UTC](https://gromacs.bioexcel.eu/t/job-submission-on-hpc-using-pbs-script/7532/1 "2023-11-02T05:03:14Z")
GROMACS version:2022.1 GROMACS modification: Yes Respected expert, ![IMG_20231102_094222](https://europe1.discourse-cdn.com/flex017/uploads/bioexcel1/original/2X/0/0b4fbed4bbb88e5650cb9508e980e6ff3f5cb188.jpeg) I am using our institute HPC for mdrun. I can utilise one node but cannot utilise multiple nodes. I have learnt that PBS.sh script(image attached)is used for job submission on our institute’s HPC Even though i have tried modifications like varying number of nodes, process per node, but no relief, job is running only on one node . Please help ---
**Author:** ![milosz.wieczor](https://avatars.discourse-cdn.com/v4/letter/m/b19c9b/32.png) [@milosz.wieczor](https://gromacs.bioexcel.eu/u/milosz.wieczor)\ **Post date:** [November 2, 2023, 3:04pm UTC](https://gromacs.bioexcel.eu/t/job-submission-on-hpc-using-pbs-script/7532/2 "2023-11-02T15:04:37Z")
Hi, As far as I know, `pmemd.MPI` is an Amber executable, so it shouldn’t be used in front of gmx\_mpi. On most clusters, one of the following should work: - `mpirun gmx_mpi mdrun ...` - `mpiexec gmx_mpi mdrun ...` - `srun gmx_mpi mdrun ...` using all the CPUs that are requested via the PBS direcrtrives. Right now, you’re requesting 5\*20=100 CPUs but trying to use `-np 24` which would anyway waste most of the resources.