R-matrix calculation of the bound and continuum states of the e(-)-NO+ system

A comprehensive theoretical study of NO Rydberg states and of Feshbach resonances associated with excited states of NO+ is made for an internuclear separation of 2.175 a(0). Calculations are performed using the UK R-matrix molecular package. The lowest four target tates (X (1) Sigma(+), a (3) Sigma(+), b (II)-I-3 and w (3) Delta) are considered in the construction of the CI target wavefunction. Quantum defect theory is employed to analyse the multiple Rydberg series obtained. In the bound-states region of the NO spectrum, six Rydberg series are resolved and quantum defects are given up to n = 11. In the continuum spectrum, Rydberg series of resonances converging to the three excited states of NO+ considered are identified and compared with available experimental data. Some previous assignments for both bound and continuum states are reinterpreted and the dominant source of partial-wave mixing re-analysed. Data for the resonance widths are presented-for the first time.