The multiple minimum problem in molecular modeling. Tree searching internal coordinate conformational space

Abstract

A general algorithm is described which exhaustively searches conformational space using an internal coordinate tree search. Using only geometrical operations and a set of criteria for eliminating chemically unreasonable structures, the algorithm generates starting geometries for optimization by molecular mechanics. An implementation of this algorithm is exceedingly fast and finds all known minima, as well as several new ones, for four test alkanes. This method makes feasible global conformational searches for molecules with up to 10⁹ conformational possibilities.