Adiabatic-to-diabatic electronic state transformation and curvilinear nuclear coordinates for molecular systems

Following an original idea of Baer, since then several times applied to various small molecular collisional systems, it is shown that — whatever the choice of curvilinear generalized coordinates to describe the molecular gometry and overall rotation — the algebraic framework proposed by Baer remains valid provided only that the exact tensorial expression of the kinetic energy operator is used.