+++
title = "Running Gaussian at HCC"
description = "How to run the Gaussian program on HCC resources."
+++

Gaussian is a popular ab inito quantum chemistry program in the field of
computational chemistry. Gaussian is a licensed program and currently
University of Nebraska-Lincoln (UNL) owns a campus wide site license for
its source codes \[G09 Src Minor Rev. (D.01)\] and a couple of
pre-compiled binaries.

All faculty/staff/students of UNL are allowed to access **g09** source
code and run the **g09** program at HCC. Collaborators of UNL faculty
may be allowed to run **g09** binaries while they are physically
visiting UNL. Note that faculty/staff/students from other branches of
University of Nebraska (NU) system including University of Nebraska
Omaha, University of Nebraska Medical Center, University of Nebraska at
Kearney are not allowed to run **g09** program at HCC without purchase
of a **g09** license.

For access, contact us at
 {{< icon name="envelope" >}}[hcc-support@unl.edu](mailto:hcc-support@unl.edu)
and include your HCC username. After your account has been added to the
group "*gauss*", here are four simple steps to run Gaussian 09 on Crane:

**Step 1:** Copy **g09** sample input file and SLURM script to your
"g09" test directory on the `/work` filesystem:

{{% panel theme="info" header="Copy sample files" %}}
{{< highlight bash >}}
cd $WORK
mkdir g09-test
cd g09-test
cp  /util/opt/gaussian/09/RevD/test_g98.com ./
cp  /util/opt/gaussian/09/RevD/run-g09-general.slurm ./
{{< /highlight >}}
{{% /panel %}}

**Step 2:** Check **g09** input file and modify it if necessary:

{{% panel theme="info" header="Review g09 input file" %}}
{{< highlight bash >}}
vi test_g98.com
{{< /highlight >}}
{{% /panel %}}

Content of Gaussian input file `test_g98.com`:
{{% panel theme="info" header="Input file `test_g98.com`" %}}
{{< highlight batch >}}
%nprocs=4  
#P RHF/6-31G\*\* scf=direct test prop=fit

Gaussian Test Job 178:  
TATB rhf/6-31g**//hf/6-31g**
Energy with tight cutoffs would be -1006.2213391, is -1006.2213170
with  
default cutoffs

0,1  
X  
C,1,RC1  
C,1,RC2,2,60.  
C,1,RC1,3,60.,2,180.,0  
C,1,RC2,4,60.,3,180.,0  
C,1,RC1,5,60.,4,180.,0  
C,1,RC2,6,60.,5,180.,0

... ...

N,7,RCN2,13,90.,1,180.,0  
H,29,RNH,7,A2,13,0.,0  
H,29,RNH,7,A2,13,180.,0

RC1=1.431682  
RC2=1.451892  
RCN1=1.431748  
RNO=1.205098  
A1=120.501393  
RCN2=1.312086  
RNH=0.990828  
A2=118.920716
{{< /highlight >}}
{{% /panel %}}


**Step 3:** Check **g09** SLURM submission script file, and modify it if
necessary:

{{% panel theme="info" header="Review SLURM submission script" %}}
{{< highlight bash >}}
vi run-g09-general.slurm
{{< /highlight >}}
{{% /panel %}}

Content of Gaussian SLURM submission file `run-g09-general.slurm`:

{{% panel theme="info" header="run-g09-general.slurm" %}}
{{< highlight batch >}}
#!/bin/sh
#SBATCH -J g09
#SBATCH --nodes=1 --ntasks-per-node=4
#SBATCH --mem-per-cpu=2000
#SBATCH --time=01:00:00
#SBATCH --partition=batch
#SBATCH --error=TestJob.%J.stderr
#SBATCH --output=TestJob.%J.stdout

nodelist > ./machines.LINUX
echo $SLURM_JOB_ID > ./jobid

module load gaussian/09/RevD
source ${g09root}/g09/bsd/g09.profile
export GAUSS_SCRDIR=$TMPDIR

g09 test_g98.com
{{< /highlight >}}
{{% /panel %}}

**Step 4:** Submit the job and wait for **g09** job to be started by the scheduler:

{{% panel theme="info" header="Submit job" %}}
{{< highlight bash >}}
sbatch run-g09-general.slurm
{{< /highlight >}}
{{% /panel %}}

Note that your account has to be a member of group "**gauss**" to run
such example.

**Some g09 restrictions you need to know:**

1.  Parallel execution of our g09 is Open-MP based:
    This means you can run **g09** only on a single node with multiple
    CPUs, e.g.
    `#SBATCH --nodes=1 --ntasks-per-node=4` with SLURM.  
    Also, make sure `%nprocs=4` in g09 input file matches with your
    CPU request in your SLURM submission file.
2.  Scratch files directory for g09:  
    `export GAUSS_SCRDIR=$TMPDIR`  
    You may override the default scratch file location by explicitly
    specifying it in your SLURM submission file for Gaussian (ie.
    `export GAUSS_SCRDIR=$PWD`).
3.  Convert .chk file to .fchk file before loading to GaussianView:  
    Type 
    {{< highlight batch >}}
    module load gaussian/09/RevD
    source ${g09root}/g09/bsd/g09.profile
    {{< /highlight >}}
    to load g09 environment.  
    Type `cd xxx` to change directory, where xxx is the directory
    including the g09 generated .chk file.  
    Type `formchk yyy.chk yyy.fchk` to convert format, where yyy is
    the file name of your .chk file before the suffix.  
      
      

#### Run g09 with [DMTCP (Checkpointing)]({{< relref "dmtcp_checkpointing" >}}):

If your **g09** job could not finish within 168 hours walltime, you may
try the following steps to checkpoint your **g09** job with dmtcp and
resume the interrupted job afterwards.

Submit your initial **g09** job with the following SLURM submission file:

{{% panel theme="info" header="Submit with dmtcp" %}}
{{< highlight batch >}}
#!/bin/sh
#SBATCH -J g09-dmtcp
#SBATCH --nodes=1 --ntasks-per-node=16
#SBATCH --mem-per-cpu=4000
#SBATCH --time=168:00:00
#SBATCH --partition=batch
#SBATCH --error=TestJob.%J.stderr
#SBATCH --output=TestJob.%J.stdout

nodelist >  ./machines.LINUX
echo $SLURM_JOB_ID > ./jobid

module load gaussian/09/RevD
source ${g09root}/g09/bsd/g09.profile
export GAUSS_SCRDIR=$PWD

rm -rf ckpt*
rm -rf dmtcp*

module load dmtcp

export DMTCP_CHECKPOINT_INTERVAL=561600
export DMTCP_HOST=localhost
export DMTCP_PORT=7779
export DMTCP_GZIP=1
export DMTCP_CHECKPOINT_DIR=$PWD
export DMTCP_SIGCKPT=12
export DMTCP_TMPDIR=/tmp

dmtcp_checkpoint g09 < au3O2-c13-pbepbegd3iop30-opt-tz.gjf > au3O2-c13-pbepbegd3iop30-opt-tz.log
{{< /highlight >}}
{{% /panel %}}

One parameter you may need to adjust is `DMTCP_CHECKPOINT_INTERVAL` which
controls the time interval in seconds for writing dmtcp checkpoint
files. Currently it is set to 561600s, namely 156 hours. In other words,
dmtcp will begin to write checkpointing files 12 hrs before the total
168 hrs walltime. The time to finish writing checkpointing files will
vary with different types of **g09** calculations. I would suggest you
to try different `DMTCP_CHECKPOINT_INTERVAL` values in
your submitted g09-dmtcp jobs to find a suitable value for your
particular type of calculation.

Once your running job completes checkpointing, make sure you see a file
called `dmtcp_restart_script.sh` generated in your job's working
directory. Then you can use the following SLURM submission file to
resume your interrupted job:

{{% panel theme="info" header="Resume with dmtcp" %}}
{{< highlight batch >}}
#!/bin/sh
#SBATCH -J g09-restart
#SBATCH --nodes=1 --ntasks-per-node=16
#SBATCH --mem-per-cpu=4000
#SBATCH --time=168:00:00
#SBATCH --partition=batch
#SBATCH --error=TestJob.%J.stderr
#SBATCH --output=TestJob.%J.stdout

nodelist >  ./machines.LINUX
echo $SLURM_JOB_ID > ./jobid

module load gaussian/09/RevD
source ${g09root}/g09/bsd/g09.profile
export GAUSS_SCRDIR=$PWD

module load dmtcp

export DMTCP_CHECKPOINT_INTERVAL=561600
export DMTCP_HOST=localhost
export DMTCP_PORT=7779
export DMTCP_GZIP=1
export DMTCP_CHECKPOINT_DIR=$PWD
export DMTCP_SIGCKPT=12
export DMTCP_TMPDIR=/tmp

./dmtcp_restart_script.sh
{{< /highlight >}}
{{% /panel %}}

{{% notice info %}}
The restarted job **will not** write the new output to the original output file
`au3O2-c13-pbepbegd3iop30-opt-tz.log`, but to the file `TestJob.%J.stdout` instead.
{{% /notice %}}