eng Oriental Scientific Publishing Company Biosciences Biotechnology Research Asia 0973-1245 2016-06-13 11 Spl.Edn.2 117 125 10.13005/bbra/1448 12022 article Aktoty Bolatovna Niyazbekova 1 Nikolay Vladimirovich Akatyev 1 Timur Askarovich Shakirov 1 West Kazakhstan State University Named M.Utemisov’s, Republic of Kazakhstan, 090000, Uralsk, Dostykstreet 162. The thermodynamic properties and equilibrium constants of cyclotri-, tetra-, penta-and hexaphosphates systems with di-and trivalent cations, p-and d-elements for different cyclophosphate / metal molar ratios equal 2:1, 1:1, 1:2 and 1:3 were calculated by using PM3 quantum-chemical semi-empirical method. It was shown that the state of systems equilibrium determines their strength and formation patterns. https://www.biotech-asia.org/vol11_nospl_edn2/quantum-chemical-modeling-of-equilibrium-state-of-systems-cyclotri-tetra-penta-and-hexaphosphates-with-di-and-trivalent-cations-of-p-and-d-elements/ Quantum-chemical calculations; Cyclophosphates; Complexation; Hydrolysis