Abstract: Structural,elastic,and electronic properties of B4,B3,and B1 ZnO under 0~15 GPa are studied with first-principles method combined with energe-of-state and elastic calculations.It shows that under 0~15 GPa,the energy of B4 ZnO is always lower than that of B3 ZnO.Either B4 or B3 transforms to B1 at a critical pressure,i.e.,11.8 GPa for B4 and 12.4 GPa for B3.As B4 transforms to B1,volume of the system reduces to about 88.3% of the initial value.The results agree with available experimental and theoretical data.The shear modulii reduce rapidly as the pressure is larger than 6 GPa,which means that some structural change may happen.It agrees with recent experimental results.Electronic properties show that the interaction between Zn 3d and O 2p reduces as the pressure increases.

Key words: first-principles, structure transformation, ZnO