Local ordering of hydroxy groups in hydroxyapatite

Abstract

Density functional theory calculations of hydroxyapatite identified the oxygen and hydrogen positions of the hydroxy groups in the crystal structure to be well defined, alternating in a column in the c-direction, and we predict that the experimentally found oxygen and hydrogen disorder is due to the presence in the crystal of differently oriented locally ordered domains, a finding which is important for studies of crystal growth and surface reactivity.