Hydroxyapatite (Ca-5(PO4)(3) OH) (HAp) is a crystalline structure and composition analogue to calcified tissues of vertebrates. The biomedical significance of HAp is its bioactivity HAp ceramics leads to the formation of new bone on their surface. HAp properties are ascribed to the characteristic surface structure of HAp, while the detailed mechanism is still unknown. Modeling and computation of HAp molecular nanostructures, exploration of the possible mechanisms of its surface charging (polarization), based on proton transfer, and the discussion of the adhesion properties of HAp nanoparticles and ceramics are the aim of the work.