CX、CX-和CX+(X=F, Cl)电子结构及振动频率的量子化学计算

用ab initio分子轨道方法和密度泛函(DFT)方法对CX、CX-和CX+(X=F，Cl)的电子结构及振动频率进行了量子化学计算，分别得到了不同电子态下的相应几何结构和理论振动频率，并在MP2/6-311+G*级别几何上进行了MP4(SDQ)和QCISD(T)组态相互作用技术的能量计算。结果表明，键长和基态能量与文献值基本一致。对于6重态中性分子和5重态阴离子，相应的几何结构、振动频率和能量分析表明分子和离子碎片基本处于解离状态。对于阴离子，其能量最低电子态不是单重态，而是3∑电子态，中性分子和阳离子的能量最低电子态分别为2∏和1∑电子态。

A quantum chemistry calculation of the electronic structures and vibrational frequencies of CX, CX- and CX+(X=F, Cl)

The structures and related vibrational frequencies are calculated using ab initio molucular orbital method and density function method. The theoretical vibrational frequencies and related structures of several different states and total energies which are corrected by MP4(SDQ)/6-311 +G* and QCISD(T)/6-311+G* using MP2/6-311+G* gemetry are gained. The results show that the bond strengths and total energies of ground states are in well agreement with the reported experimental results.The bond lengths, frequencies, and total energies analysis proved that the CF, CCl which are in hexadet and the CF-, CCl- which are in quintette are on the edge of dissociation. The electronic ground state of CF- or CCl- is 3∑ state, not single. The electronic ground states of CF or CCl, and CF+, CCl+ are 2II and 1∑, respectively.