For symmetric tetraatomic molecules (ABBA), it is convenient to introduce the symmetry coordinates corresponding to the trans and cis bending by the vector relations [Pg.627]

ABA symmetry, Renner-Teller effect, triatomic molecules, 618-621 ABBA molecules, Renner-Teller effect, tetraatomic molecules [Pg.66]

We restrict ourselves again to symmetric tetraatomic molecules (ABBA) with linear eqnilibrium geometi7. After integrating over electronic spatial and spin coordinates we obtain for A elecbonic states in the lowest order (quartic) approximation the effective model Hamiltonian H — Hq+ H, which zeroth-order part is given by Eq. (A.4) and the perturbative part of it of the form [Pg.539]

In this section, we consider H electronic state (A = 1) of ABBA type molecules. The additional Hamiltonian H is of the form [Pg.523]

© 2019 chempedia.info