Molecular order variation with position

The H-bonded species in Fig. 5.5 exhibit smooth variations of H-bond length and strength with respect to position in the periodic table, in a manner consistent with the expected ordering (5.36b) of Lewis-acid strengths. In each case the inter-molecular interaction is dominated by the no->aAH donor-acceptor stabilization shown in the right-hand panel. Energetic, geometrical, and vibrational properties of... 

The V-B coupling Hamiltonian to first order in the three HOD dimensionless normal coordinates is Hv b = —2, c], l , where F, is the inter-molecular force due to the solvent exerted on the harmonic normal coordinate, evaluated at the equilibrium position of the latter. This force obviously depends on the relative separations of all molecules, and on their relative orientations. In the most rigorous quantum description of rotations, this term would depend on the excited molecule rotational eigenstates and of the solvent molecules. Instead rotation was treated classically, a reasonable approximation for water at room temperature. With this form for the coupling, the formal conversion of the Golden Rule formula into a rate expression follows along the lines developed by Oxtoby (2,53), with a slight variation to maintain the explicit time dependence of the vibrational coordinates (57),... 

---