甲醚的分子结构及振动光谱的理论研究

采用密度泛函理论（DFT）方法（BLYP、B3LYP）、从头算HF和MP2方法在6－31^*水平上对甲基醚的几何构型、振动谐性场和红外光谱进行了研究，使用Pulay标度法对各方法计算得到的理论力场进行标度，标度轭了分别为：：0．09、3：0．96，HF:0．89，MP2：0．94，根据标度后的理论力场进行了简正坐标分析，得到势能分布和红外振动频率，与实验红外频率相比，发现经标度后，4种方法的标准偏差均在30cm^-1左右，结果较好，此外，还根据B3LYP方法得到的势能分布和分外强度，对甲基醚的振动基频进行了理论归属。

THEORETICAL STUDIES OF STRUCTURES AND VIBRATIONAL FREQUENCIES OF DIMETHYL ETHER

Density functional theory BLYP, B3LYPand ab initio HF, MP2 calculations were carried out to study the structure and vibrational spectra of dimethyl ether. Molecular conformation calculations were made for two possible conformers of the compound.The results show that:the stable conformer is the staggered one; The BLYP/6-31G* and scaled frequencies correspond well with each other and with available experimental assignment of the normal vibrational modes. On the basis of the comparison between calculated and experimental results, assignments of fundamental vibrational modes are examined.