非传统超导PuCoGa_5晶体结构和电子性质的密度泛函理论研究

Structural and Electronic Properties of Nonconventional Superconductor PuCoGa_5:Density Functional Study

基于密度泛函理论的全势能线性缀加平面波方法(FLAPW),采用局域自旋密度近似(LSDA)及LSDA+U方法报道了Pu基超导体系PuCoGa_5的晶格参数,原子占位和电子性质.LSDA+U方法不仅考虑Pu-5f而且考虑了Co-3d的库伦排斥作用U和Hund交换相关作用J.结果表明LSDA+U在同时考虑Pu和Co的强关联作用时晶格参数和原子占位与相关理论和实验数据吻合较好,特别是PuCoGa_5中Pu-5f的强定域特征尤其是自旋向下的电子.此外,Pu-5f与Co-3d电子的轨道杂化明显强于Ga-4p电子.

Lattice parameters,atom positions and electronic structure of Pu-based superconductor PuCoGa5 are studied with local spin density approximation（LSDA） and LSDA ＋ U method of full potential linear augmented plane wave（FLAPW） method based on density functional theory.LSDA＋U formalism was used to account for the strong on-site Coulomb repulsion among localized Pu 5f and Co 3d electrons.It shows that results of LSDA＋U considering strong correlation between Pu and Co agrees well with relevant theoretical and experimental data,especially,PuCoGa5 Pu-5f strong domain features of electronic spin down.In addition,orbital hybridization between Pu-5f and Co-3d is obviously stronger than that of Ga-4p.