Phase changes study of the InP crystal under external stress

The ultrasoft pseudopotential plane method was used to calculate and analyze the electronic structure of the InP crystal under external stress. Results of calculations of the energy band structure show that with increasing external stress, the InP crystal band gap decreases until it disappears at 18 Gpa. Under external stress, the calculation and analysis of the state density and Mulliken electronic population illustrates that the energy band structure changes in InP are mainly due to changes in the distribution of In atom 5s and 5p conduction band electrons and the P atom 2p upper valence band electrons. In terms of structural changes in the electronic system, the In atom 5p and P atom 2p electrons play the dominant role. Under stress, the In-P bond becomes more covalent.