JUSTUS2/Software/Gaussian

Name
module load	chem/gaussian
Availability	bwForCluster_Chemistry
License	commercial
Citing	See Gaussian manual
Links	Homepage; Manual; IOps Reference
Graphical Interface	Yes, Gaussview

Description

Gaussian is a general purpose quantum chemistry software package for ab initio electronic structure calculations. It provides:

• ground state calculations for methods such as HF, many DFT functionals, MP2/3/4 or CCSD(T);
• basic excited state calculations such as TDHF or TDDF;
• coupled multi-shell QM/MM calculations (ONNIOM);
• geometry optimizations, transition state searches, molecular dynamics calculations;
• property and spectra calculations such as IR, UV/VIS, Raman or CD; as well as
• shared-memory parallel versions for almost all kind of jobs.

For more information on features please visit Gaussian's Overview of Capabilities and Features web page.

Versions and Availability

A current list of the versions available on the bwUniCluster and bwForClusters can be obtained from the Cluster Information System: CIS Information on Gaussian.

On the command line interface (CLI) of a particular bwHPC cluster a list of all available Gaussian versions can be inquired as followed

$ module avail chem/gaussian

Parallel computing

The Gaussian Module provides serial and shared-memory parallel binaries automatically at the same time. Switching between the serial and parallel version is done via

%NProcShare=PPN

statement in section Link 0 commands before the route section at the beginning of the Gaussian input file. PPN should be replaced by the number of parallel cores. This value must be identical to the ppn value specified when requesting resources from the queueing system. Since Gaussian is shared-memory parallel, only single node jobs do make sense. Without NProcShare statement the serial version of Gaussian is selected.

Usage

Loading the Module

You can load the default version of Gaussian with command:

$ module load chem/gaussian

The Gaussian Module does not depend on any other Module.

If you wish to load a specific version you may do so by specifying the version explicitly, e.g.

$ module load chem/gaussian/g09.D.01

to load version g09.D.01 of Gaussian.

Running Gaussian interactively

After loading the Gaussian module you can run a quick interactive example by executing

$ time g09 < $GAUSSIAN_EXA_DIR/test0553-8core-parallel.com

In most cases running Gaussian requires setting up the command input file and piping that input into g09.

Creating Gaussian input

For documentation about how to construct input files see the Gaussian manual. In addition the program Gaussview is a very good graphical user interface for constructing molecules and for setting up calculations. Finally these calculation setups can be saved as Gaussian command file.

Disk Usage

By default, scratch files of Gaussian are placed in GAUSS_SCRDIR as displayed when loading the Gaussian module. Except for short tests please never run Gaussian calculations in your $HOME or $WORK directory.

Examples

Single node jobs

Queueing system template provided by Gaussian module

The Gaussian module provides a simple Moab example of Hexanitroethan (C2N6O12) that runs an 8 core parallel single energy point calculation using method B3LYP and basis set 6-31g(df,pd). To submit the example do the following steps:

$ ws_allocate calc_repo 30; cd $(ws_find calc_repo)
$ mkdir my_first_job; cd my_first_job
$ module load chem/gaussian
$ cp -v ${GAUSSIAN_EXA_DIR}/{bwforcluster-gaussian-example.moab,test0553-*.com} ./
$ msub bwforcluster-gaussian-example.moab

The last step submits the job example script bwforcluster-gaussian-example.moab to the queueing system. Once started on a compute node, all calculations will be done under an unique directory on the local file system ($TMPDIR) of that particular compute node. Please carefully read this local file system documentation as well as the comments in the queueing system example script bwforcluster-gaussian-example.moab.

Version-Specific Information

For specific information about version VERSION see the information available via the module system with the command

$ module help chem/gaussian/VERSION

Please read the local module help documentation before using the software. The module help contains links to additional documentation and resources as well as information about support contact.

---