Potential energy distributions

Amadei, A., Apol, M. E. F., Di Nola, A., Berendsen, H. J. C. The quasi-Gaussian entropy theory Free energy calculations based on the potential energy distribution function. J. Chem. Phys. 104 (1996) 1560-1574... 

It has been shown that the potential energy distribution provides an approximate method to evaluate the relative contribution of each symmetry coordinate to a given normal mode of vibration. From the definition of the symmetry coordinates, the relation... 

Descriptions are based on the calculated potential energy distributions ... 

Major bond stretching contributor to the potential energy distribution ... 

Figure 2-9 Potential energy distribution in the c >—plane for a pair of peptide units with alanyl residues calculated using potential parameters of Scheraga and Flory. Contours are drawn at intervals of 1 kcal (4.184 kj) per mol going down from 0 kcal per mol. The zero contour is dashed.

Calculated frequencies (cm-1) Approximate potential-energy distributions" Calculated frequencies (cm-1) Approximate potential-energy distributions... 

Calculated29 Frequencies and Computed, Potential-Energy Distribution of Cellulose I... 

The amide VI mode is mainly CO out-of-plane bend in terms of the potential energy distribution from various internal coordinates. However, the N and H atoms are also displaced and influence the relative intensity of this mode. 

Table 2. Frequencies and Potential Energy Distributions for Formic Acid Vapor3... 

Observed Calculated Error Potential Energy Distribution (%)h... 

However, it is important to exercise caution in comparison with other force-fields for similar molecules as was shown in the case of JV-methylacetamide [5], The differences in calculated force constants is the result of using different basis sets. It is noteworthy that the potential energy distributions are not greatly different in the tables for vapor and aqueous phase. This suggests that alteration of the force... 

In the multicanonical ensemble [11,12], on the other hand, each state is weighted by a non-Boltzmann weight factor Wmn E) (which we refer to as the multicanonical weight factor), so that a uniform potential energy distribution Pmu E) is obtained ... 

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