FRACTAL PHENOMENA IN MOLECULAR MECHANICS CALCULATION

It is proposed that in molecular mechanics calculation points belongin g to various stable or meta-stable conformers are mixed up and form fr actal structures in conformation space. The calculation results show t he following two phenomena: (i) Two levels of structure with fractal f eature were observed. Around the conformer without mirror symmetry, po ints belonging to the conformer and its enantiomer are mixed up and fo rm the first level of fractal structure; on the boundary of the attrac tive basin of each attractor, points belonging to different attractors form the second level of fractal structure. (ii) The variation of mol ecular mechanics parameters will influence the structure and area of e ach attractive basin significantly. The above phenomena may become the basis of a new method for solving the troublesome multi-minimum-point problem in molecular mechanics calculation.