Coupling energies computation

We note that the standard state, infinite-dilution chemical potential, involves only solute-solvent interactions, since the coupling energy in the Boltzmann factor in Eq (3.61) is computed with no other solute molecules present. If finite solute concentrations lead to more favorable Boltzmann factors, then y < 1, and vice versa for less favorable interactions. Also, as Xq, 0, y 1, as expected. 

J. F. Stanton and J. Gauss, in Recent Advances in Coupled-Cluster Methods, R. J. Bartlett, Ed., World Scientific Publishing, Singapore, 1997, pp. 49-79. Analytic Evaluation of Second Derivatives of the Energy Computational Strategies for the CCSD and CCSD(T) Approximations. 

Fig. 7 Product ro-vibration distributions for H+H2(v = OJ = 0) for different total energies computed using the lower adiabatic PES including the diagonal non-Bom-Oppenheimer term without (IS-NGP) and with (IS-GP) the GP, and using the coupled diabatic surfaces (2S-DIABATIC). Reprinted with permission from [39]. Copyright (2008) by the American Institute of Physics...

However, the absolute values of activation energies computed for vinyl-vinyl coupling are significantly lower than that for methyl-methyl couphng. Particularly, AE" =49.8 kcal/mol (MP4//MP2 level) [39a], AE "=60.8 kcal/mol (MP4//HF) [39b,c], and AH =41.1 kcal/mol (GVB) [37a] were reported for ethane reductive elimination from [Pt (CH3)2(PH3)2]. The values are much higher than AE =1... 

The optimized geometries and resulting energies for the reactants, entrance complex, transition state, exit complex, and products were predicted. Harmonic vibrational frequencies predicted at the same level (up to cc-pVQZ and cc-pVQZ-PP basis sets) were used for the characterization of stationary points and zero-point vibrational energies (ZPVE). The CFOUR program of Stanton, Gauss, Harding, Szalay, and coworkers was used for the coupled-cluster computations [24]. Most DZ results are not shown in text, but they are available in Supplementary Material. 

Miyake et al have investigated the structures and enhanced reactivity of isomeric hexacoordinated dihydrophosphates (Fig. 15c). As a part of this work, the authors optimized geometries of isomeric compounds, calculated atomic charges, relative molecular energies, and J(P,H) couplings. The computing of j was carried out at the B3PW91/6-31-fG(d,p)//MP2/6-31- -G(d,p) theory levels. 

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