Q-Chem

Short Description

"Q-Chem is a comprehensive ab initio quantum chemistry package. Its capabilities range from the highest performance DFT/HF calculations to high level post-HF correlation methods."

Version

3.2.0.2

Modulefile

none

Documentation

Q-Chem Website

Version 3.2 manual

Usage

Here is an example of a submission script:

#$ -cwd
#$ -l h_rt=01:00:00
#$ -l qchem=true
#$ -pe ompi* 4

export QC=/usr/local/qchem
source $QC/bin/qchem.setup.sh
# Uncomment the following to use NQS -- see Notes
# export QCSCRATCH=/nqs/$USER/qchem   
qchem -np $NSLOTS input.inp

Notes

• Q-Chem is licensed node-by-node. To ensure Grid Engine dispatches your job to a licensed node, include the resource request "-l qchem=true".
• Q-Chem can be used with any parallel environment. If you have no specific reason to use another, we recommend -pe ompi*.
• Scratch files are by default written in (and erased from) /home/$USER/qchem. Be careful if you are using the directory of this name for other purposes. You can direct Q-Chem to write its scratch files elsewhere by setting the environment variable QCSCRATCH.
• If you wish to use NQS to get more space for QCSCRATCH, you must first understand what NQS is and apply for access to it as described here.
• If you wish to use node-local scratch to improve performance, be sure you read about QCLOCALSCR in the Q-Chem manual and about Local Scratch on the Storage System page. You might also wish to contact support.
• Q-Chem may create hidden files (files with prefix ".") in the course of execution. If you find yourself cleaning up after an aborted run, you should use ls -a to make sure you got everything.
• Q-Chem can also be accessed through WebMO at Placentia only.