EXPERIMENTAL AND THEORETICAL-STUDY OF THE B-NE NONBONDING INTERACTION - THE FREE-BOUND B (2)SIGMA(+)-X (2)PI ELECTRONIC-TRANSITION

We report a new investigation of the interaction between atomic boron, in both the ground 2p P-2 and excited 3s S-2 electronic States, with Ne. BNe complexes are formed in a pulsed free jet expansion and detected by laser fluorescence excitation. A broad, asymmetric feature is seen, with maximum intensity similar to 270 cm(-1) to the blue of the 3s S-2-2p P-2(J) atomic transition. This feature corresponds to electronic excitation from the ground vibrational level of the BNe(X (II1/2)-I-2) State into the BNe(B (2) Sigma(+)) state, which is unbound. High level ab initio configuration-interaction calculations, involving large atomic;orbital bases, were carried out to describe the relevant:potentials. The potential curve for the B state reveals a broad shoulder, but no well. The calculated potential curves are corrected, very slightly, by an additional scaling of the correlation energy. Spectral simulations based on these corrected curves reproduce, nearly quantitatively, the experimental spectrum; (C) 1995 American Institute of Physics.