CaS、SrS的LMTO-ASA能带计算中d态的作用

d State Fffects in LMTO-ASA Band Structure Calctulations of CaS and SrS

CaS和SrS晶体的能带结构,LAPW和Hartree-Fock方法的计算结果差别很大,前者为间接带隙而后者为直接带隙,本文在LMTO-ASA计算方法中,采用两种不同处理d态的计算方案,分别得到与LAPW和Hartree-Fock两种计算方法对应的能带结构,研究了空d态处理方法对Cas和SrS能带结构计算结果的影响。

The results of band structure of CaS and SrS crystal based on LAPW method aredifferent from the results calculated by Hartree-Fock method. The LAPW predicts that CaS and SrS arc indrect-band-gap materials but the Hartree-Fock predicts they arc direct-band -gap materials. In our LMTO ASA calculations of this article,two d state schemes are taken into into account,and we get two different results which are consistent with LAPW result and Hartree-Fock result tespcctivty. We also have studied the influence of empty d states on band -structure calculations of CaS and SrS.