A new approach to probing conformational space with molecular mechanics: random incremental pulse search

• Published in: Journal of the American Chemical Society Vol. 111; no. 12; pp. 4371 - 4378
• Main Authors: Ferguson, David M, Raber, Douglas J
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01.06.1989
• Subjects: 400000 - Chemistry; 400200 - Inorganic, Organic, & Physical Chemistry; 990200 - Mathematics & Computers; ALKANES; Atomic and molecular physics; CALCULATION METHODS; Calculations and mathematical techniques in atomic and molecular physics (excluding electron correlation calculations); CONFORMATIONAL CHANGES; CYCLOALKANES; Electronic structure of atoms, molecules and their ions: theory; ENERGY; Exact sciences and technology; GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE; HYDROCARBONS; INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; MATHEMATICAL MODELS; MOLECULAR MODELS; MONTE CARLO METHOD; ORGANIC COMPOUNDS; Physics; POTENTIAL ENERGY; Saturated cyclic compound; Hydrocarbon; Twist angle; Force field method; Potential surface; Theoretical study; Calculating method; Organic compounds; Conformation
• ISSN: 0002-7863; 1520-5126
• DOI: 10.1021/ja00194a034

A computational method is described that permits reliable searching for different molecular conformations. A Monte Carlo type routine is employed to randomly search the potential energy surface for a given molecule, and Allinger's MM2 force field is employed for energy calculations and minimizations. The method has two modes of operation: conformational search (by torsional or energetic criterion) and global minimum location. The Monte Carlo type routine, called random incremental pulse search (RIPS), logically couples the benefits of random searching with those of analytical minimization. The method has been tested by searching conformational space for a series of cycloalkanes. All conformational families and minimum-energy structures are reliably located in each case.