First-principles calculations based on the density-functional theory were employed to study the crystal structure of vanadium phosphide compounds,such as V3P,V2P,VP,VP2 and VP4. Cohesive energy of five types of vanadium phosphide compounds was calculated to assess their structural stability. The charge density distribution and densities of states of vanadium phosphides were discussed to study further their electronic structures. The results show that the structure of metal-rich compounds is considerably more stable than the phosphorus-rich compositions,and covalent bond exists between the V and P atoms of V3P,V2P,VP,VP2 and VP4.
First-principles calculations based on the density-functional theory were employed to study the crystal structure of vanadium phosphide compounds, such as V3P, V2P, VP, VP2 and VP4. Cohesive energy of five types of vanadium phosphide compounds was calculated to assess their structural stability. The charge density distribution and densities of states of vanadium phosphides were discussed to study further their electronic structures. The results show that the structure of metal-rich compounds is considerably more stable than the phosphorus-rich compositions, and covalent bond exists between the V and P atoms of V3P, V2P, VP, VP2 and VP4.