In a generalization of the latest achievements in this field, and as a pattern of massive
applications, we present here the Jahn–Teller effect (JTE) and pseudo-JTE (PJTE) as …

A recently developed scheme to produce accurate high-dimensional coupled diabatic
potential energy surfaces (PESs) based on artificial neural networks (ANNs)[J. Chem. Phys …

Spatial degeneracy of electronic states closely connects spin–orbit coupling and vibronic
coupling, which together determine properties of materials, especially heavy element …

While fundamental to molecular quantum mechanics, limitations of the Born-Oppenheimer
Approximation (BOA) have long been known. Nonetheless, calculations that include …

In this study, we examine the adiabat‐to‐diabat (ATD) angles for trajectories in 2‐
dimensional vibrational subspace of the seam space of two degenerate states. In circulating …

The diabatization of reactive systems for more than just a couple of states is a very
demanding problem and generally requires advanced diabatization techniques. Especially …

We derive expansion formulas up to arbitrary order in vibrational coordinates for the
tetrahedral and octahedral vibronic Hamiltonians that involve T and E states, and t and e …

A formalism for expansions of all Jahn–Teller and pseudo-Jahn–Teller Hamiltonian
operators in all axial symmetries is presented. The formalism provides Hamiltonian …

Recently, the negative ion photoelectron spectrum of CO3− was reported and the second
lowest energy band is assigned to the close-lying 3E′′ and 3E′ states that undergo Jahn …

The Jahn–Teller (JT) and pseudo-Jahn–Teller (PJT) effects in the 2E, Ã2E and 2A1
electronic states of the propyne radical cation are investigated with the aid of ab initio …