Molecular geometry energy diagram

Fig. 15. Molecular orbital energy diagram for an AB5 molecule with the square pyramidal geometry. (No s orbital interaction.)...

An advanced supplement to reference 13 gives molecular energy level diagrams for different molecular geometries. 

Correlation diagram A diagram which shows the relative energies of orbitals, configurations, valence bond structures, or states of reactants and products of a reaction, as a function of the molecular geometry, or another suitable parameter. An example involves the interpolation between the energies obtained for the united atoms and the values for the separated atoms limits. 

Surface crossing In a diagram of electronic energy versus molecular geometry, the electronic energies of two states of different symmetry may be equal at certain geometrical parameters. At this point (unidimensional representation), line or surface (more than one dimension), the two potentialenergy surfaces are said to cross one another. 

SCF-A a method (a) geometry of the (FeTiO,o) cluster (b) molecular-orbital energy-level diagram for the cluster a and p spin are spin-up and spin-down electron orbitals energy levels indicated by dashed lines are unoccupied (c) calculated wave-function contours for the 16 orbitals of the cluster the I6a, orbital corresponds to the d Fe(f,. ) orbital and is clearly Fe-Ti bonding in character (after Sherman, 1987b reproduced with the publisher s permission). 

Ab initio Calculations The structure of gas-phase ions can also be determined using molecular orbital calculations [46]. The ab initio calculations permit an estimation of the AHf values and equilibrium geometries of ions, from which the potential energy diagrams can be constructed. These diagrams reveal the mechanistic pathways for isomerization and decomposition reactions and estimates of the energy barriers involved in these reactions. 

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