Energy Gradients in Combined Fragment Molecular Orbital and Polarizable Continuum Model (FMO/PCM) Calculation

Authors

Hui Li, University of Nebraska - LincolnFollow
Dmitri G. Federov, National Institute of Advanced Industrial Science and Technology, JapanFollow
Takeshi Nagata, National Institute of Advanced Industrial Science and Technology, Japan
Kazuo Kitaura, National Institute of Advanced Industrial Science and Technology, Japan
Jan H. Jensen, University of Copenhagen
Mark S. Gordon, US Dept of Energy, Ames IAFollow

Date of this Version

2009

Document Type

Article

Citation

Journal of Computational Chemistry, Volume 31, Issue 4 (2009), pp. 778-790; DOI 10.1002/jcc

Comments

US govt work.

Abstract

The analytic energy gradients for the combined fragment molecular orbital and polarizable continuum model (FMO/PCM) method are derived and implemented. Applications of FMO/PCM geometry optimization to polyalanine show that the structures obtained with the FMO/PCM method are very close to those obtained with the corresponding full ab initio PCM methods. FMO/PCM (RHF/6-31G* level) is used to optimize the solution structure of the 304-atom Trp-cage miniprotein and the result is in agreement with NMR experiments. The key factors determining the relative stability of the a-helix, b-turn and the extended form in solution are elucidated for polyalanine.