Structural, Electronic Properties and Chemical Bonding of Borate Li₄CaB₂O₆ under High Pressure: an Ab Initio Investigation

We calculate structural, electronic properties and chemical bonding of borate Li₄CaB₂O₆ under high pressure by means of the local density-functional
pseudopotential approach. The equilibrium lattice constants, density of states, Mulliken population, bond lengths, bond angles as well as the pressure dependence of the band gap are presented. Analysis of the simulated high pressure band structure suggests that borate Li₄CaB₂O₆ can be used as the semi-conductor optical material. Based on the Mulliken population analysis, it is found that the electron transfer of the Li atom is very different from that of other atoms in the studied range of high pressures. The charge populations of the Li atom decrease with the pressure up to 60GPa,
then increase with the pressure.