关键词: 第一性原理, Ca, 电子结构, 线性缀加平面波, 芯能级, 化学位移

Abstract: The first principles all-electron linearized augmented plane wave film method in the local density functional approximation is employed to investigate the electronic structure of the seven-layer Ca(100) slab system. The partial valence charges in muffin-tin spheres for various atom types, the layer projected local state densities of valence band, and the centroid shifts of 3d, 4s and 4p bands are given. The calculation shows that the core-level eigen-energies for surface atom are about 0.55eV lower than those of central atom, which can be attributed to the contribution of both the spill-out of s, p-like valence charge to vacuum and the narrowed of surface atom 3d band originated from the reduction of coordinate.

Key words: first principles, Ca, electron structure, LAPW, corelevel, chemical shift