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采用基于量子力学的半经验哈密顿量的计算方法,即SCED-LCAO方法,模拟研究了碳硅二炔的稳定性结构、成键特点、电子结构等性质.得出其最稳定的结构是单层平面结构,晶格常数为12.251 A.它通过含有两个Si-C三键的链连接六元环构成.这种平面结构在很大高温范围内都可以保持其稳定特性,直到1520 K时,该基本结构才被破坏,且结构中出现四元环.体系温度低于1520 K时,均可通过降温,恢复其零温时的结构.研究还发现这种共轭结构中Si,C原子间存在稳定的sp杂化形式,对分布函数得出其键长为1.58 A左右.高温时sp杂化逐渐转变成其他杂化形式.计算结果表明,在零温下,该电中性系统中存在离域π键,使得系统中的Si-C键长呈现平均化趋势.研究表明,碳硅二炔的能隙为1.416 eV,LUMO,HOMO能级分别是0.386 eV和1.03 eV表明了其n型半导体特性.
The semi-empirical Hamiltonian method based on quantum mechanics (SCED-LCAO) is used to simulate the stability structure, bond formation, electronic structure and other properties of carbosadiynyme.The results show that the most stable structure is single Layer plane structure with a lattice constant of 12.251 A. It consists of a six-membered ring connected by a chain containing two Si-C triple bonds, which maintains its stable properties over a wide range of high temperatures up to 1520 K , The basic structure was destroyed, and the four-membered ring appeared in the structure.It was found that when the temperature of the system is lower than 1520 K, the structure at zero temperature can be recovered by cooling down.The results also show that the Si, C atoms There exists a stable sp hybridization between the two species, and the distribution function shows that the bond length is about 1.58 A. The sp hybridization gradually transforms into other hybrid forms at high temperature.The calculated results show that at zero temperature, The presence of delocalized π bonds results in an averaged Si-C bond length in the system.The results show that the energy gap of carbosilane is 1.416 eV, the LUMO and HOMO levels are 0.386 eV and 1.03 eV, respectively, Semiconductor characteristics.