Ab-initio Electronic Structure Calculations of a −,b − and g − KNO3 Energetic Materials

Abstract

We have computed energy bands and density of states (DOS) of different temperature dependent phases (namely a ,b andg ) of
potassium nitrate (KNO3). The band structure computations have been performed using linear combination of atomic orbitals scheme within density functional theory (LCAO-DFT) with local density approximation and generalized gradient approximation. Moreover, to see the role of hybrid Hartree Fock and DFT Hamiltonian, we have employed Becke’s three parameter hybrid functional calculations. The present LCAO-DFT calculations indicate that there exists a direct band gap for α- and g − KNO3, while in the case of b − KNO3 an indirect band gap is found. It is observed that the LCAO-GGA calculations show a better agreement with the experimentally observed band gap. An explosive nature of KNO3 is also discussed in terms of energy bands and density of states.