CH_3F分子间相互作用的ab initio研究

Ab initio Study on the Intermolecular Interaction of CH_3F

在 MP2 /6-31 1 ++G( 3d,3p)电子相关校正水平上 ,对 CH3F二聚体可能存在的几何构型进行全自由度能量梯度优化和频率验证 ,发现 3种势能面上有极小点的构型 .进一步在高级电子相关校正的 MP4 S-DTQ、CCSD( T) /6-31 1 ++G( 3df,3pd)方法水平上 ,对其中总能量最小的构型进行精确计算 ,得到二聚体的结合能为 -9.70 7k J/mol.研究结果支持了由光谱实验结果推测的构型 ,解释了

Various possible structures of the CH 3F dimer have been optimized at the MP2/6 311++G( 3d,3p ) electron correction level, three minimum geometrical structures have been found on the potential energy surface. At a high order electron correction MP4SDTQ and CCSD(T)/6 311++G( 3df,3pd ) level, the binding energy of the most stable structure which is planar cyclic C 2h symmetry of the dimer has been calculated exactly and the binding energy Δ E CP CCSD(T) is -9.707 kJ/mol. The calculated results of the harmonic vibrational frequencies of three minimum geometries support the structures guessed by the spectra experiment. Diversity of the harmonic vibrational frequency has been explained.