AB-INITIO CALCULATIONS OF THE ROVIBRATIONAL STATES OF HE2N2+

The low-lying rovibrational states of the B-2(1) ground electronic sta te of He2N2+ were calculated using ab initio techniques. A 74 point po tential energy surface was constructed using the CCSD(T) method couple d with a cc-pCVTZ basis set. The CCSD(T) optimised equilibrium geometr y was of C-2v symmetry with an R(N-He) bond length of 1.329 Angstrom a nd a theta(He-N-He) bond angle of 88.6 degrees. The discrete potential energy surface was fitted using a Pade (4, 5) power series expansion, yielding a(chi(2))(1/2) of 9.98 x 10(-5) au. The potential function w as embedded in the nuclear Schrodinger equation and solved variational ly to yield the low-lying rovibrational states.