Self-consistent molecular relaxation by simulated annealing

Abstract

A method analogous to that of Car and Parrinello (Phys. Rev. Lett., 1985, 55, 2471) can be used simultaneously to relax atomic positions and calculate LCAO wavefunctions for systems for which electron–lattice coupling is important and the ground-state geometry is not known. In this paper, the method is outlined, with particular reference to the study of conjugated polymers. In addition to the ground-state geometry and wavefunctions, the extent of the lattice distortion around a typical defect is also found, in terms of a change of the dimerisation pattern.