Beta相氮化硅的电子结构

用局域密度泛函理论和ＬＭＴＯ－ＡＳＡ方法计算了氮化硅β－Ｓｉ３Ｎ４的电子结构。由于采用了Ｌｏｗｄｉｎ微挠理论，在保证能量精度的条件下，大大减少了计算工作量。通过三种不同空原子球设置方案的能带计算结果的比较，详细讨论了在开结构晶体能带计算中的空原子球设置（包括空原子球的数目，位置和半径）对能带的影响。结果表明，空原子球的合理设置对于得到正确开结构材料的能带结构，特别是导带结构是重要的。本文结果和第一原理赝势法得到的能带相吻合。

Electronic Structure of β-KSi_3N_4

Electronic structure of silicon nitride,β-Si3N4,was calculated by local density functional theory and LMTO-ASA method cooperated with the use of Lowdin perturbation technique that saved computation time considerably and insured the computation accuracy. On the bases of calculated energy bands from the three different settings of the empty atomic spheres,the effects of setting (e. g. the number,positions and radius of the empty atomic spheres)on the energy band were discussed in details. It has been shown that the reasonable setting of empty atomic spheres is important for the widely opened crystal structures to obtain the correct energy band,especially correct conduction band.The energy band of the presented calculation is in good agreement with that of the ah initio pseudopotential calculation.