LSDA+U方法研究PuO_2电子结构和成键特征

LSDA+U study on electronic structure and bonding characteristic of PuO_2

采用LSDA(局域自旋密度近似)+U(有效库仑相关能)方法计算研究了PuO2的电子结构和成键特征。计算的平衡体积和半导体带隙分别为0.03875 nm3和0.18 eV,与实验结果符合得很好。能态密度和电子密度的分析表明PuO2并不是纯粹的离子晶体,Pu5f和O2p轨道杂化形成共价键。计算结果有助于理解PuO2晶体中Pu5f电子的关联效应。

The LSDA＋ U approach combining with the local spin density approximation （LSDA） of density functional theory and the effective Coulomb correlation energy （U） has been used to calculate electronic structure and bonding characteristic of semiconductor PuO2. The calculated equilibrium volume of 0. 03875 nm^3 and band gap of 1.8 eV are both in good agreement with experimental data. The analysis of density of states and electron density shows that the chemical bond in bulk PuO2 is not pure ionic and the covalent bond is formed by PuSf orbital hybridizing with O2p orbital. The results provide some basis for understanding correction effect of Pu5felectrons.