title: Quantum chemistry in parallel with PQS.
abstract: This article describes the capabilities and performance of the latest release (version 4.0) of the Parallel Quantum Solutions (PQS) ab initio program package. The program was first released in 1998 and evolved from the TEXAS program package developed by Pulay and coworkers in the late 1970s. PQS was designed from the start to run on Linux-based clusters (which at the time were just becoming popular) with all major functionality being (a) fully parallel; and (b) capable of carrying out calculations on large-by ab initio standards-molecules, our initial aim being at least 100 atoms and 1000 basis functions with only modest memory requirements. With modern hardware and recent algorithmic developments, full accuracy, high-level calculations (DFT, MP2, CI, and Coupled-Cluster) can be performed on systems with up to several thousand basis functions on small (4-32 node) Linux clusters. We have also developed a graphical user interface with a model builder, job input preparation, parallel job submission, and post-job visualization and display.
authors.affiliation: Parallel Quantum Solutions, 2013 Green Acres Road, Suite A, Fayetteville, Arkansas 72703, USA. baker@pqs-chem.com
authors.forename: Jon
authors.initials: J
authors.lastname: Baker
authors.forename: Krzystof
authors.initials: K
authors.lastname: Wolinski
authors.forename: Massimo
authors.initials: M
authors.lastname: Malagoli
authors.forename: Don
authors.initials: D
authors.lastname: Kinghorn
authors.forename: Pawel
authors.initials: P
authors.lastname: Wolinski
authors.forename: Gábor
authors.initials: G
authors.lastname: Magyarfalvi
authors.forename: Svein
authors.initials: S
authors.lastname: Saebo
authors.forename: Tomasz
authors.initials: T
authors.lastname: Janowski
authors.forename: Peter
authors.initials: P
authors.lastname: Pulay