Crystal field model equilibria

The first semiempirical studies of the potential functions of silatranes revealed that their Si-<—N bond could be very easily deformed by crystal packing and solvation forces . Direct MINDO/3 and MNDO calculations demonstrate a significant shortening of the equilibrium, gas phase Si- —N distance due to the contribution of the solute-solvent interaction energy (within the Onsager reaction field model ) to the total enragy of 1-methyl- and 1-fluorosilatranes . 

The bundle model of polymer crystallization will be discussed first. This mean-field approach describes the metastable configurational equilibrium of the undercooled polymer chain in solution or in the melt, and we will summarize and update previous work of ours [7-9]. The concept of the bundle, i.e. an aggregate of a few parallel polymer segments or stems connected by folds (see Fig. 1 see also [10]) and stabilized by attractive crystal-like interac-... 

Most of the four above-mentioned properties for Raman spectra can be explained by using a simple classical model. When the crystal is subjected to the oscillating electric field = fioc " of the incident electromagnetic radiation, it becomes polarized. In the linear approximation, the induced electric polarization in any specific direction is given by Pj = XjkEk, where Xjk is the susceptibility tensor. As for other physical properties of the crystal, the susceptibility becomes altered because the atoms in the solid are vibrating periodically around equilibrium positions. Thus, for a particular... 

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