Hydroxyapatite-constituting cluster;

Investigation of a stable cluster through ab initio calculation 3

Abstract

The potential energy surface on the [Ca₃(PO₄)₂]₃ was studied through ab initio calculations. Isomers with T_d, T_h and 2D_3d symmetries was found to be the most appropriate starting points. From these symmetries, 137 different isomers were formed in their subgroups in total. Among the 137 isomers, 67 isomers have at least two operations of symmetry. The bond length and angle of Ca-O within the 67 isomers were optimized. The isomers corresponding to the first, second and third lowest energy calculated are of Cs, S₆ and C₂ symmetry, respectively.