Orellana W, da Silva A J, Fazzio A
Instituto de Física, Universidade de São Paulo, CP 66318,05315-970, São Paulo SP, Brazil.
Phys Rev Lett. 2001 Oct 8;87(15):155901. doi: 10.1103/PhysRevLett.87.155901. Epub 2001 Sep 20.
We address the diffusion of the oxygen molecule in SiO2, using first-principles spin-polarized total-energy calculations. We find that the potential energy surfaces for the singlet and triplet states are very different in certain regions, and that the O2 molecule preserves its spin-triplet ground state not only at its most stable interstitial position inside the solid but also throughout its diffusion pathway. Therefore, the singlet state is not a good approximation to describe the behavior of O2 inside SiO2, and spin-polarization effects are fundamental to understand the properties of this system.
我们利用第一性原理自旋极化总能计算方法，研究了氧分子在二氧化硅中的扩散。我们发现，单重态和三重态的势能面在某些区域有很大差异，并且O₂分子不仅在固体内部最稳定的间隙位置保持其自旋三重态基态，而且在整个扩散路径中都保持该状态。因此，单重态不是描述O₂在二氧化硅内部行为的良好近似，自旋极化效应对于理解该系统的性质至关重要。
