An Accurate and Efficient Development of QM/EFP: Parallelization
Tosaporn Sattasathuchana, Peng Xu, Mark S. Gordon
Department of Chemistry, Iowa State University, Ames, Iowa, 50011, USA
Email: tsatta@iastate.edu
An interface of quantum mechanics (QM) and the effective fragment potential (EFP) was implemented for a treatment of explicit solvation models with inclusions of Coulomb, polarization, exchange repulsion, and dispersion interactions. New implementations of the QM/EFP approach are developed to reduce the intensive computational times and the large amount of disk usage by utilizing a direct method for the two-electron integrals of QM/EFP exchange repulsion. A parallel QM/EFP approach is established with numerical stability and highly accurate energetic predictions. The CPU efficiencies between the conventional and on-the-fly twoelectron integrals of QM/EFP for S22 data set are compared in terms of computational times for both serial and parallel calculations. The new parallel implementation with the direct approach of QM/EFP two-electron integrals significantly increases the percentages of CPU utilizations.