Excitation energy electronic partition

Partition of electronic excitation energy in various pathways fo anthracene and its derivatives in presence of 02... 

In most cases, excited electronic energy levels lie high above the ground-state energy relative to ksT, and the population in the upper levels is negligibly small. In these cases the electronic partition function reduces to one term ... 

Thus, even in this very high temperature example, excited electronic energy levels make a negligible contribution to the electronic partition function. 

The electronic partition function can be evaluated by summing over spectroscopically determined electronic states, but as the electronic energy-level separations are large, the number of molecules in excited electronic states is negligibly small at ordinary temperatures and the electronic partition function is unity and will be ignored henceforth. 

Partitioning technique in electron transfer and excitation energy transfer... 

Partitioning Technique in Electron Transfer and Excitation Energy Transfer 11... 

Table 1. Hierarchy of coupled cluster methods for response calculations. The table summarizes to which order in the electron fluctuation potential ground state and single excitation energies and response functions are obtained correctly at a given level of the correlation treatment. The analysis is based on a Mpller-Plesset like partitioning of the Hamiltonian as H(t, e) = F+ U + V t, e), where U is the electron fluctuation potential [58, 59]...

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