โ Scribed by S. Yamada; M. Nakano; H. Nagao; K. Yamaguchi
No coin nor oath required. For personal study only.
We investigated an interesting behavior in electron correlation and ลฝ . structure dependencies of the second hyperpolarizability โฅ of the ethylene model. The โฅ values of the ethylene model with plain and twisted structures were examined using various ab initio MO methods. โฅ was found to be largely changed depending on the rotation angle of the CH group in ethylene. The rotation-angle dependence of โฅ is 2 remarkably different among HartreeแFock and higher-order electron-correlation results. By applying hyperpolarizability density analysis, it was found that there are negative and positive contributions to โฅ and that, especially, electrons play an important role to determine the rotation-angle dependence of โฅ at high-order electron correlation levels.
๐ SIMILAR VOLUMES
The static electronic longitudinal polarizability โฃ and second ## ลฝ . hyperpolarizability โฅ of all-trans planar polyacetylene chains have been computed at ลฝ . different levels of approximation by varying the bond length alternation BLA along the ลฝ . conjugated backbone. Although the restricted Ha
Ab initio calculations have been performed for F 2 , HCCH, H 2 O, HF, (HF) 2 , and (H 2 O) 2 , comparing certain electron pair correlation methods, or methods for doubly substituted configurations. In these model systems, the reweighting of substituted configurations that occurs beyond a second-orde
between the two extreme conformations of a keto and an eno form. The keto form is more stable in the gas phase and the eno form is believed to be more stable in solution. We show that the keto form can prevail in nonpolar solvents, but in polar solvents like chloroform, the eno form should be domina
The third-order nonlinear optical properties (second molecular hyperpolarizabilities, y), of a series of organoboron compounds containing dimesitylboron moieties have been investigated by third harmonic generation (THG) measurements at 1.907 pm. Symmetric systems with B(mes), groups (mes = 2,4,6-Me,