ADIABATIC AND DIABATIC POTENTIAL-ENERGY SURFACES OF THE CN(X-2-SIGMA(+),A(2)PI)NE COMPLEX AND NONADIABATIC PREDISSOCIATION DYNAMICS

Adiabatic and diabatic potential-energy surfaces (PES's) for the inter action of Ne(S-1(0)) with the CN molecule in its ground (X (2) Sigma()) and first excited (A (2) Pi) electronic states were determined usin g multireference configuration-interaction calculations. The three ele ctronically adiabatic potential-energy surfaces (PES's, 2 A' and 1 A ' ') are transformed to three diabatic PES's plus one additional PES whi ch describes the coupling between the two diabatic PES's of A' symmetr y which correlate asymptotically with the X (2) Sigma(+) and A (2) Pi states of CN. These four diabatic PES's are then used in the study of the predissociation of the CN(A 2 Pi)Ne complex, subsequent to electro nic excitation of the ground-state complex [CN(X)Ne]. Two channels: Fa st spin-orbit predissociation [CN(A (2) Pi(1/2), upsilon = 3)Ne --> CN (A (2) Pi(3/2), upsilon = 3) + Ne] and slow electronic predissociation [CN(A (2) Pi(3/2), upsilon = 3)Ne --> CN(X (2) Sigma(+), upsilon = 7) + Ne] are investigated. The quantum flux method was used to determine the positions and widths of the metastable levels of the complex. For these predissociation processes, comparison is made with the experime ntal investigation by Fei, Lawrence, Chen, and Heaven. (C) 1997 Americ an Institute of Physics.