Theoretical calculations of the high-pressure phases of SnO2

Total-energy calculations of tin dioxide, done at seven different phases under conditions of hydrostatic pressure in the rutile, CaCl2-type, α-PbO2, pyrite, ZrO2 orthorhombic, fluorite, and cotunnite structures using first principle full potential-linearized augmented plane wave (FP-LAPW) plus local orbitals method within the density functional theory (DFT). The structural properties at equilibrium as at high pressure are investigated by using generalized gradient approximations (GGAs) that are based on the optimization of total energy. For band structure calculations, both GGA and modified Becke–Johnson (mBJ) of the exchange–correlation energy and potential, respectively, are used. Pressure–temperature dependent thermodynamic properties including the bulk modulus, thermal expansion, Debye temperature, heat capacity and Grüneisen parameter, are calculated using model based on the quasi-harmonic approximation (QHA).