First-principles calculations of the electronic structure of crystalline silicon and its dioxide were performed on the basis of the density functional theory. The full-potential linearized augmented plane waves method was used with the generalized gradient approximation for the exchange-correlation potential with Perdew, Burke and Ernzerhof functional. X-ray absorption near edge structure of silicon L₃ spectra for these materials were calculated with the use of core-hole approach and supercells. These calculated spectra were used as reference for modeling the X-ray absorption L₃ spectrum of a real silicon sample covered with a layer of natural SiO₂ oxide. Comparison of the spectra obtained by the first principles calculations with the results of a high-resolution synchrotron experiments and the suggested approach to their modeling demonstrated the possibility of a complex silicon-oxygen system prospective materials and structures detailed study.

根据密度泛函理论，对晶体硅及其二氧化物的电子结构进行了第一性原理计算。对Perdew，Burke和Enzzerhof泛函的交换相关势使用了全势线性化增强平面波方法和广义梯度近似法。这些材料的硅L ₃光谱的边缘结构附近的X射线吸收是通过使用核孔法和超级单元计算的。这些计算的光谱用作建模天然硅₂层覆盖的真实硅样品的X射线吸收L ₃光谱的参考氧化物。通过第一原理计算获得的光谱与高分辨率同步加速器实验的结果以及所建议的建模方法进行比较，证明了可能进行复杂的硅氧系统前瞻性材料和结构的详细研究。