Experimental and theoretical investigation of the A P–X R transition of NH/D–Ne

A study of NH/D–Ne was undertaken to investigate the structure of this complex and examine the ability of high-level theoretical methods to predict its properties. The A P–X S transition was characterized using laser induced fluorescence measurements. Results from theoretical calculations were used to guide the interpretation of the spectra. Two-dimensional potential energy surfaces were calculated using second-order multireference perturbation theory with large correlation consistent basis sets. The potential energy surfaces were used to predict the ro-vibronic structure of the A–X system. Calculated ro-vibronic energy level patterns could be recognized in the spectra but quantitative discrepancies were found. These discrepancies are attributed to incomplete recovery of the dynamical correlation energy.