AB-INITIO STUDY OF THE ELECTRONIC-SPECTRUM OF THE NCL2 RADICAL

The equilibrium geometries, excitation energies, force constants and vibrational frequencies for the low-lying electronic states X(2)B(1), (2)A(1) B-2(2) and (2)A(2) Of the NCl2 radical have been calculated at the MRSDCI level with a double-zeta plus polarization basis set. Our calculations indicate that the X B-2(1) --> (2)A(2) transition may correspond to the (X) over tilde --> (A) over tilde band system which lies between 275 and 314 nm in the absorption spectrum reported in A.G. Briggs and R.G.W. Norrish, Proc. R. Soc. London, A278 (1964) 27; T.C. Clark and M.A.A. Clyne, Trans. Faraday Soc., 65 (1969) 2994; V.V. Azatyan, R.R. Borodulin and N.M. Rubtsov, Dokl. Akad. Nauk SSSR, 249 (1980) 1375; V.V. Azatyan, R.R. Borodulin and N.M. Rubtsov, Dokl. Phys. Chem., 249 (1980) 1056. Our calculated excitation energies for X B-2(1) --> (2)A(1) and X B-2(1) --> (2)A(2), vibrational frequencies for the X B-2(1) and (2)A(2) states and the geometry for the X B-2(1) State are in agreement with available experimental data. The electronic transition dipole moments, oscillator strengths for the (2)A(1) --> X B-2(1) and (2)A(2) --> X B-2(1) transitions and radiative lifetimes for the (2)A(1) and (2)A(2) states are calculated based on the MRSDCI wavefunctions, predicting value of the radiative lifetime for the (2)A(1) State also in reasonable agreement with experiment