Hidden JTE

Fig. 1 Illustration of two cases of hidden JTE (a) Excited state JTE overcomes the energy gap to the ground state producing a global minimum with a distorted configuration (the ground state A is nondegenerate) (b) PJTE between two excited states produces a global minimum with a distorted configuration...

The first type of hidden JTE defined above is generated by an excited state with a strong JTE. A straightforward example of such a hidden JTE, the ozone molecule O3, was considered recently [11]. Ab initio calculations of the electronic structure of this molecule were performed by a number of authors. Eigure 2 shows some of the results obtained by means of high-level ab initio calculations for the ground state with geometry optimization [12-14]. 

The hidden pseudodegeneracy that causes SSB [55, 57] seems to be even more important (and even more hidden ) than the hidden degeneracy. In hidden-pseudodegeneracy-induced SSB via the PJTE, similar to the case of hidden JTE,... 

As shown below, it comes out that in all cases when the JT origin of distortions is not seen explicitly, the instability is still due to the JTE, but the latter is hidden in the excited states of the high-symmetry configurations. 

Fig. 2 Illustration of the origin of the distortion in the global minimum due to the JTE hidden in the excited state it takes place when the JT stabilization energy jt is larger then the energy gap A to the ground state of the high-symmetry configuration and in the direction of the JT-active coordinate...

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