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Benchmarking Localized Coupled Cluster methods in the NWchem package


EMSL Project ID
3552

Abstract

Using the Tensor Contraction Engine developed by Dr. So Hirata
we have implemented a localized coupled cluster approach in
NWchem. The present and near-future capabilities of this implementation
include
1) AO-based CCSD approach that can run in parallel
2) Localized occupied orbital CCSD approach in which most of the
amplitudes are estimated at the MBPT[2] level and a subset is
calculated at the CCSD level. The selection MBPT[2] vs. CCSD is done
dynamically.
3) Integral direct implementations of the above methods.

We wish to benchmark these methods for medium sized to
large molecules, e.g. naphtalene to porphyrin, using large
AO basis sets (cc-PVTZ or cc-PVQZ). The benchmarking
includes
1) A comparison of the full CCSD vs. CC/MBPT methods.
2) An analysis of the parallel performance of the algorithm
3) Feasibility studies of large scale AO-based CC/MBPT methods
concerning time, memory and disk space resources.

Project Details

Project type
Exploratory Research
Start Date
2003-06-26
End Date
2005-08-02
Status
Closed

Team

Principal Investigator

Martinus Nooijen
Institution
University of Waterloo