α-ZnP_2物态方程的密度泛函理论研究

The DFT study of the equation of state for α-ZnP_2

利用密度泛函理论（DFT），分别采用广义梯度近似（GGA）和局域密度近似（LDA）对α—ZnP2在0～40GPa范围内的结构进行相关的分子动力学模拟，得到了它的压强-体积（P—V）关系．用不同形式的物态方程对它的P—V关系进行了拟合．拟合结果表明，Vinet物态方程较好的反映了α—ZnP2的体积随压强的变化；与LDA相比，用GGA得到的体积弹性模量B0值与实验值符合的更好．

In the framework of the density functional theory （DFT）, the structure of the a modification of zinc diphosphide （α-ZnP2） at the pressure from zero to 40 GPa is investigated by using molecular dynamics （MD） simulation, in which both the local density approximation （LDA） and the generalized gradient approximation （GGA are employed. On the basis of the pressure-volume （P-V） relationship for α-ZnP2, several types of equauons of state （EOS） are selected to fit its P-V relationship. As a result, Vinet EOS gives a good description of the dependence of volume on pressure for α-ZnP2. And compared with the experimental value, the bulk modulus B0 obtained by GGA is a little better than LDA.