“…Because of the lower Cs symmetry the La state possesses the same symmetry (A') as the ground state. Therefore, this state with its electronic configuration 25a'2-26a'27a', which is derived from the configuration [ 14a¡9a^12b¡ 11 b^] 12bz 15a, in Civ notation, can mix with the ground state configurations [...]12b| (now 25'226a'2) and [...]15af (now 25a'227a'2), and the actual mixing is sizable in the area in which the configurations have similar energy, i.e., in the region of the ground state barrier. As a consequence, the adiabatic (Cl) potential energy curves (Figure 7) of the La state possesses typical La-type character until RC = 0.3, the character of the second Lb state of the Dewar form for RC > 0.…”