Longuet-Higgins

Longuet-Higgins H C 1956 The electronic states of composite systems Proc. R. Soc. A 235 537... 

Stillinger F 1973 Structure in aqueous solutions from the standpoint of scaled particle theory J. Solution Chem. 2 141 Widom B 1967 Intermolecular forces and the nature of the liquid state Sc/e/ ce 375 157 Longuet-Higgins H C and Widom B 1964 A rigid sphere model for the melting of argon Mol. Phys. 8 549... 

Longuet-Higgins [7] also reinforces the discussion by tbe following qualitative demonstration of a cyclic sign change for the LiNaK like system subject to Eq. (3), in which rows and columns are labeled by the basis functions... 

Appendix A The Jahn-Teller Model and the Herzberg-Longuet-Higgins Phase Appendix B The Bom-Oppenheimer Treatment Appendix C Formulation of the Vector Potential References... 

APPENDIX A THE JAHN-TELLER MODEL AND THE HERZBERG-LONGUET-HIGGINS PHASE... 

Longuet-Higgins corrected the multivaluedness of the elechonic eigenfunctions by multiplying them with a phase factor, namely,... 

V. Longuet-Higgins Loops and the Jahn-Teller Theorem... 

Longuet-Higgins stated and proved the following theorem [13] ... 

The proof runs analogously to the original Longuet-Higgins one, and is not reproduced here. 

The Woodward-Hoffmann method [52], which assumes conservation of orbital symmetry, is another variant of the same idea. In it, the emphasis is put on the symmetries of molecular orbitals. Longuet-Higgins and Abramson [53] noted the necessity of state-to-state correlation, rather than the orbital correlation, which is not rigorously justified (see also, [30,44]). However, the orbital symmetry conservation rules appear to be very useful for most themial reactions. 

In this section, the systematic search for conical intersections based on the Longuet-Higgins phase-change rule is described. For conciseness sake, we limit the present discussion to Hiickel-type systems only, unless specifically noted otherwise. The first step in the antilysis is the determination of the LH loops containing a conical intersection for the reaction of interest. 

V. LONGUET-HIGGINS LOOPS AND THE JAHN-TELLER THEOREM... 

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