(H2O)2和(HCl)2非线性光学性质的从头计算研究

用MP2方法及aug-cc-pVDZ,aug-cc-pVDZ+BF,aug-cc-pVTZ和aug-cc-pVTZ+BF基组对(H2O)2和(HCl)2超分子的静态偶极矩μ0,极化率α0及第一超极化率β0进行计算.采用Counterpoise方法消除基组的重叠误差(BSSE),得到上述物理性质的分子间相互作用的贡献,在此基础上研究了其中新的长程π型氢键的效应.

Ab initio Study on the Nonlinear Optical Properties of (H2O)2 and (HCl)2

The static dipole moments(μ0), polarizabilities(α0) and first hyperpolarizabilities (β0) of (H2O)2 and (HCl)2 dimers are investigated by means of ab initio methods with various basis sets, ADZ, ADZ+BF, ATZ, and ATZ+BF at MP2 level. Through analysis and comparison, we found that the results of the dimers are convergent when the basis sets are not less than ATZ and the electron correlation is important. In order to show the contributions from intermolecular interactions to nonlinear optical properties, the counterpoise method is applied. The calculated results show that the μz and β0 values of hydrogen bonding dimers (H2O)2 and (HCl)2 are smaller than those of the sums of the values of subsystems. In addition, for μz and β0, the ratios of contribution from π type H bond to that of the total intermolecular interactions in the β0 properties are small.