There are four surface state bands in the gap. Among them, two occupied surface state bands have been confirmed by valence band spectra of synchrotron radiation photoelectron spectroscopy.
在带隙附近存在四个表面态带，其中的两个占有表面态带已由价带的同步辐射光电子能谱实验得到证实。
2
The fourth sub-band is occupied by exteriorized beings who are still attached to the "reality of physical matter", although they do realize that they have become exteriorized .