Order of M.O. energies

It is rather difficult to have preconceived ideas about the order of M.O. energies from Eq. (4). The closest analogy of a dioxo complex with unusually short internuclear distances may be C02 having the ionization energies (in eV) determined by photo-electron spectra49)... 

There is general agreement today that the order of M. O. energies in tetroxo complexes is... 

Fig. 3.1. Order of M.O. energies on the basis of number of nodes in them.

If Koopmans theorem is not obeyed, the order of m.o.s indicated by the spectrum will not correspond to that present in the neutral molecule. Even so, much useful information can be derived from studying the photoelectron spectra of series of closely related complexes. In this way the effect of changing ligand substituents for example, on the relative energies of molecular orbitals can be investigated. 

Consider an elementary cubic lattice with elastic modulus E and free surface energy 7. The elastic strain energy per atom due to biaxial strain of magnitude em is on the order of Ee o. On the other hand, the in-plane chemical bonding energy per atom is on the order of 2 af. For a choice of parameters oi E = 10 N/m, 7=1 J/m, Cm = 0.02, and af = 0.3nm, the... 

The vibrational relaxation of simple molecular ions M+ in the M+-M collision (where M = 02, N2, and CO) is studied using the method of distorted waves with the interaction potential constructed from the inverse power and the polarization energy. For M-M collisions the calculated values of the collision number required to de-excite a quantum of vibrational energy are consistently smaller than the observed data by a factor of 5 over a wide temperature range. For M+-M collisions, the vibrational relaxation times of M+ (r+) are estimated from 300° to 3000°K. In both N2 and CO, t + s are smaller than ts by 1-2 orders of magnitude whereas in O r + is smaller than t less than 1 order of magnitude except at low temperatures. 

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