Spin excitation energy

E, Jf, J[ Excitation, spin Excitation energy and spin of final state... 

Kolos, W., J. Chem. Phys. 27, 591, Excitation energies of C2H4. The correlation between electrons with opposite spins is estimated by multiplying the usual orbital wave functions by the inter-electronic distance. 

Expressions have been given by Sohn, Hendrickson, and Gray (48) for the excitation energies of the three spin-allowed one-electron d-d transitions, and for the corresponding spin-forbidden transitions. Since these partial results already include all the singly excited states for d6, Cocv, systems, the use of the full matrices (Table 5) will usually have only a minor effect on the fitting parameters. It should be noted that the one-electron excitation... 

Here at least nine dissociative channels are theoretically accessible below the ionization threshold. The dissociation products are NH2 -NH + H2, NH2 + H, or NH + 2H (final state), of which NH and NH2 may exist either in the ground or an excited state. Production of molecular hydrogen is negligible at low excitation energies, but it can account for 15% or more of the dissociation processes when the excitation exceeds -7 eV Note that the lowest excited state of NH3 ( 4 eV) does dissociate into NH and H2 but is spin forbidden. 

The solute electronic time scale will be called Telcc It may be approximated as h/A j, where A j is the lowest (spin-allowed) electronic excitation energy of the solute. 

Table 9.1 presents excitation energies for a few atoms and ions. Calculations were performed with the generalized KLI approximation [69,74], For comparison, experimental data and the results obtained with the local-spin-density (LSD) exchange-correlation potential [75] are shown. The KLI method contains only the exchange. 

Table 1 Spin-Free Excitation Energies in Re2Cls (in eV) Calculated at the CASSCF (CAS) and CASPT2 (PT2) Level.

The possible fate of excitation energy residing in molecules is also shown in Figure 2. The relaxation of the electron to the initial ground state and accompanying emission of radiation results in the fluorescence spectrum - S0) or phosphorescence spectrum (Tx - S0). In addition to the radiative processes, non-radiative photophysical and photochemical processes can also occur. Internal conversion and intersystem crossing are the non-radiative photophysical processes between electronic states of the same spin multiplicity and different spin multiplicities respectively. 

Table 4. CASPT2 excitation energies for the Pt atom including the effect of spin-orbit coupling...

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