Electronic Structure, Optical Properties, and Pressure Behavior of the CdB4O7 and HgB4O7 Compounds

Shinkorenko, A. S.; Zinenko, V. I.; Pavlovskii, M. S. Source: PHYSICS OF THE SOLID STATE, 60 (9):1704-1711; 10.1134/S1063783418090305 SEP 2018

Ab initio calculations of the structural, electronic, and optical properties of the CdB4O7 and HgB4O7 tetraborate compounds in three structural modifications with the Pbca, Cmcm, and Pmn21 symmetry have been performed in the framework of the density functional theory using the VASP package. The calculations of the electronic band structure showed that these compounds in all the investigated modifications are dielectrics with a band gap of 2–4 eV. The calculation of the structural properties of the tetraborates under pressure showed that the phase transition between the Pbca and Pmn21 structures in cadmium and mercury tetraborates occurs under pressures of 4.8 and 4.7 GPa, respectively.