Electronic configurations and states

The two highest occupied MOs (i = 1, A = 2) and the two lowest unoccupied MOs (r - V and k = T) are shown. Depending on the magnitude of the interaction, the HOMO- LUMO transition corresponds approximately to the lowest or to the second-lowest excited state. 

Within the PPP approximation the singlet and triplet Cl matrices for an alternant hydrocarbon each factor into two separate matrices for the plus states and the minus states corresponding to the linear combinations 

The ground state behaves like a minus state since it interacts only with minus states excited configurations of the type however, behave like plus states. In this approximation the transition moments between two plus states or two minus states vanish, and such transitions are forbidden. Electric dipole transitions are allowed only between plus and minus states (Pariser, 1956). 

For anthracene, for the state that is characterized by the HOMO- LUMO excitation, we have 

The interaction between two configurations and 4 i, increases with the increasing absolute value of the matrix element the decreasing absolute value of the difference of the energies of the two configurations. If two configurations and belong to different irreducible rep- 

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Figure 1.12 Electronic configurations and state diagram for the octahedral complex Rufbpy). Only the lower-lying states are shown...

The state with highest M-value is the 3P(MS=1, Ml=1) state. As shown in Chapter 10 which deals with electronic configurations and states, this particular product... 

Table 6.3. Ground state electron configurations and states for homonuclear diatomic molecules in the first row of the periodic table...

However there is a problem with this dicussion for many pseudo-octahedral d complexes. 29 shows the electronic configurations and states expected for a d trans MY4Y2 complex (D4h). Whether the ajg or bjg level lies lowest in energy (and hence the or Aig state) will depend upon the relative o strength of the ligands, but does not influence our discussion. From the symmetry demands of the relaxation term of Eq. 11 the sym-... 

Fig. 5a and b. Correlation diagram for electron configurations and states in the cyclobutene-butadiene interconversion a) conrotatory motion, b) disrotatory motion... 

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