Zero-order electro-optical parameters

Zero-order electro-optical parameters for CH4, C2H6, C2H4, C2H2, CfiHg, CH2CI2 and CHCI3 (in units of A2)... 

Tx is the transpose of the Tx matrix and U matrix has its usual meaning. The first summation in Eq. (9.52) comprises the zero-order electro-optical parameters. The fluctuations of bond polarizability a(k) with changes in length and spatial orientation of the same bond are only considered. The second term is responsible for the first-order intensity parameters. All internal coordinates are considered less the stretching of bond k. 

The number of unknowns in the set of equations (9.41) is, thus, reduced. Still, however, the number of parameters (nine) exceeds the number of equations (seven). It is evident that some parameters have to be constrained equal to zero in order to obtain a defmite set of equations. If da2/dr and da- ld parameters are set equal to zero, the following set of electro-optical parameters is obtained (in units of or A3 rad" )... 

In zero-order approximation of the bond polarizability model the following three types of electro-optical parameters representing derivatives of the bond polarizability with respect to bond displacement coordinates are defined [296,297]... 

In the fi-amework of the compact formulation of bond polarizability theory the computational procedure is significantly simplified and appropriate for computer programming. A package of computer programs has been developed [312]. The approach developed allows for factorization of the physical properties of the molecule. Thus, Ox, Oy, Oz and SoW/SRi depend mainly on electro-optical properties of the molecule while the -vectors - on the molecular geometry and atomic masses. The contributions of zero-order reop and first-order parameters to do/dSj are clearly separated, as well. 

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