Electronic, bond order, linear optical properties of series of alkalimetal P-O-P linkage borophosphates

Abstract

A series of P-O-P linkage alkalimetal borophosphates are studied based on the experiment and plane-wave pseudopotential technology within the density function theory (DFT). The structural chemistry of fundamental building units, electronic structure, and linear optical properties are discussed in terms of materials. To elucidate the character of P-O-P linkage in borophosphates which violates Pauling's fourth rule, two simulated isomer clusters were built, one in the absence of P-O-P linkage and the other with the existence of it. The results of bond order value demonstrate that P-O bond in B-O-P linkage is relatively stronger than that in P-O-P linkage. Population analysis is also used to further explain the feature of P-O bond. Electronic structure and absorption edge are analysed and discussed in detail based on experiments and calculations. The calculated birefringence is quite small for the anionic framework constructed of BO4 and PO4 tetrahedra.