How to use different versions of gromacs from the same machine

User discussions
1

GROMACS version: 2020.5 and 2019.6
GROMACS modification: Yes/No

I want to use two distinct versions of gromacs on my computer. For specific reasons, I want to use 2020.5 and 2019.6 as well. I installed 2020.5 initially, but realized I also need 2019.6 as well.

In order to run both versions, I need to be able to call them with different names. I want to use the 2019 version with gmx_19 and the 2020.5 version with gmx_20.

To do so, I obtained the 2019.6 version, untarred it and ran the falling script:
The untarred file is in /home/user/software/gmx_19

#!/bin/bash
module purge
module load intel/19.1/64/19.1.1.217
module load openmpi/intel-19.0/3.1.3/64
module load cudatoolkit/11.2
module load rh/devtoolset/9

cd gromacs-2019.6
mkdir build
cd gromacs-2019.6/build/
suffix=196g
cd …/…

install_path=/home/user/software/gmx_2019/local

OPTFLAGS="-Ofast -mtune=broadwell"
cmake3 … -DCMAKE_BUILD_TYPE=Release
-DCMAKE_C_COMPILER=icc -DCMAKE_C_FLAGS_RELEASE="$OPTFLAGS"
-DCMAKE_CXX_COMPILER=icpc -DCMAKE_CXX_FLAGS_RELEASE="$OPTFLAGS"
-DGMX_MPI=ON -DGMX_OPENMP=ON
-DGMX_GPU=CUDA -DGMX_CUDA_TARGET_SM=60
-DGMX_SIMD=AVX2_256 -DGMX_DOUBLE=OFF
-DGMX_FFT_LIBRARY=mkl
-DGMX_DEFAULT_SUFFIX=OFF -DGMX_BINARY_SUFFIX=_${suffix} -DGMX_LIBS_SUFFIX=_${suffix}
-DCMAKE_INSTALL_PREFIX=${install_path}

make -j 8

I believe this will let me call gromacs using gmx_196g. However, when this script runs, I still cannot call gromacs with gmx_196g. I type in gmx_196g -h and it simply says
-bash: gmx_196g: command not found

Can someone advise me on how to run two gmx versions from the same machine?

2

Each time you wish to use a different version, you need to source the relevant GMXRC file in the bin subdirectory of that installation. That will configure your environment to find and use those executables.

3

Thank you for your answer @jalemkul! sorry, but what do you mean by source? I see the GMXRC file, do you mean I should execute it so ./GMXRC?

4

The command is source GMXRC

5

This is my bin directory:

    demux.pl  gmx-completion.bash           GMXRC       GMXRC.csh  xplor2gmx.pl
    gmx_196g  gmx-completion-gmx_196g.bash  GMXRC.bash  GMXRC.zsh

I did

source GMXRC

I type in gmx_196g -h and I still am getting -bash: gmx_196g: command not found…