(1. 中南大学 粉末冶金国家重点实验室，长沙 410083;
2. 中南大学 材料科学与工程学院，长沙 410083)
摘 要: 根据固体与分子经验电子理论，通过键距差(BLD)方法，计算了金属间化合物MoSi2的价电子结构和理论结合能。结果表明，MoSi2理论结合能为1 677.1 kJ/mol，与实验值吻合。由于Si原子偏移，沿〈001〉方向分布的Si—Si原子键共价电子数最多，nD=0.402 04。MoSi2晶体中含有较高密度的晶格电子，使MoSi2具有良好的导电性。MoSi2晶体中键络分布不均匀性是导致晶体脆性的主要原因。
关键字: 二硅化钼；价电子；结合能；脆性
cohesive energy calculation of MoSi2
（1. State Key Laboratory of Powder Metallurgy, Central South University,Changsha 410083, China;
2. School of Materials Science and Engineering, Central South University,Changsha 410083, China）
Abstract:According to the empirical electron theory of solid and molecule, the valence electron structure and theoretical cohesive energy of MoSi2 were calculated by the BLD method. The results show that the theoretical cohesive energy of MoSi2 is 1 677.1 kJ/mol, which agrees well with the experimental data. Because of a shift in Si positions, the valence electrons between Si—Si atoms along <001> direction are the most (nD = 0.402 04). There are lattice electrons with higher densities in MoSi2, which accounts for the good conductivity of MoSi2. Also, it is speculated that the brittleness of MoSi2 can be explained primarily by a heterogeneity of bond distribution.
Key words: molybdenum disilicide; valence electron; cohesive energy; brittleness
