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

Document Type

Article

Date of this Version

2009

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.