Potential Energy Surface-Based Automatic Deduction of Conformational Transition Networks and Its Application on Quantum Mechanical Landscapes ofd-Glucose Conformers

• DOI: 10.1021/acs.jctc.6b00439
• Publication Date: 2016-09-28T08:24:40Z
• Authors: Hiroko Satoh; Tomohiro Oda; Kumiyo Nakakoji; Takeaki Uno; Hiroaki Tanaka; Satoru Iwata; Koichi Ohno
• Keywords: Conformational isomerism; Maxima and minima; Potential energy surface; Energy landscape

This paper describes our approach that is built upon the potential energy surface (PES)-based conformational analysis. automatically deduces a transition network, called reaction route map (r-map), by using Scaled Hypersphere Search of Anharmonic Downward Distortion Following method (SHS-ADDF). The PES-based search has been achieved large ADDF, which makes it possible to trace only low state (TS) barriers while restraining bond lengths and structures with high free energy. It performs sampling minima TS simply taking into account mathematical feature PES without requiring any priori specification variable internal coordinates. An obtained r-map composed equilibrium (EQ) conformers connected routes via conformers, where all are already confirmed during process deduction intrinsic coordinate (IRC) method. postcalculation analysis deduced interactively carried out RMapViewer software we have developed. presents computational details its application d-glucose. calculations performed for an isolated glucose molecule in gas phase at RHF/6-31G level. α-d-glucose 201 EQ 435 β-d-glucose 202 371 conformers. For r-maps program found multiple minimum paths (MEPs) between global 1C4 4C1 chair conformations. allows us confirm thermodynamic kinetic predominance conformations; is, lower than (thermodynamic predominance) highest those along from (kinetic predominance).