Department of Physics, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan.
J Phys Condens Matter. 2013 Feb 13;25(6):065505. doi: 10.1088/0953-8984/25/6/065505. Epub 2013 Jan 18.
Photoabsorption cross-sections of simple metals are formulated through a solid-state band theory based on the orthogonalized-plane-wave (OPW) method in Slater's local-exchange approximation, where interband transitions of core and conduction electrons are evaluated up to the soft x-ray regime by using large basis sets. The photoabsorption cross-sections of a sodium crystal are computed for a wide photon energy range from 3 to 1800 eV. It is found that the numerical results reproduce the existing x-ray databases fairly well for energies above the L(2,3)-edge (31 eV), verifying a consistency between solid-state and atomic models for inner-shell photoabsorption; additional oscillatory structures in the present spectra manifest solid-state effects. Our computed results in the vacuum ultraviolet regime (6-30 eV) are also in better agreement with experimental data compared to earlier theories, although some discrepancies remain in the range of 20-30 eV. The influence of the core eigenvalues on the absorption spectra is examined.
简单金属的光吸收截面是通过基于 Slater 局域交换近似的正交平面波（OPW）方法的固态能带理论来构建的，其中通过使用较大的基组评估了芯电子和导带电子的带间跃迁，直至软 X 射线区。计算了从 3 到 1800 eV 宽的光子能范围内的钠晶体的光吸收截面。结果发现，数值结果在 L（2,3）边缘（31 eV）以上的能量范围内与现有的 X 射线数据库相当吻合，验证了内壳层光吸收的固态和原子模型之间的一致性；本谱中的附加振荡结构表现出固态效应。与早期理论相比，我们在真空中紫外区（6-30 eV）的计算结果与实验数据也更加吻合，尽管在 20-30 eV 的范围内仍存在一些差异。还研究了芯能级对吸收光谱的影响。
