High resolution vacuum ultravioiet emission spectrum of D_2:The B' ~1∑_u~+- X~1∑_g~+ band system

摘要

In this work,we have extended our previous high resolution study of the vacuum ultraviolet emission spectrum of the D_2 molecule [M.Roudjane,et al.J.Chem.Phys.125,214305(2006)] up to 124.2 nm in order to investigate the B' ~1∑_u~+->X~1∑_g~+ band system.The analysis of the spectrum has been carried out by means of a complex spectrum visual identification code IDEN [V.I.Azarov,Phys.Scr.44,528(1991);48,656,(1993)] and supported by theoretical calculations using ab initio data [L.Wolniewicz,J.Chem.Phys.103,1792(1995);99,1851(1993);G.Staszewska and L.Wolniewicz,J.Mol.Spectrosc.212,208(2002);L.Wolniewicz and G.Staszewska,220,45(2003)] which provided level energies and transition probabilities.More than 1480 new emission lines have been observed and 109 bands belonging to the B' ~1∑_u~+->X~1∑_g~+ system have been identified between 84.1 and 121.6 nm.Except for the v'-0 bands that were reported in absorption [I.Dabrowski and G.Herzberg,Can.J.Phys.52,1110(1974)],all the v'-v"bands are reported here for the first time.The analysis led to the determination of 111 rovibronic energy levels in the B' ~1∑_u~+ state,of which 31 with higher rotational numbers J are new.Observed perturbations are accounted for through a set of coupled equations involving the four excited electronic states B~1∑_u~+,B' ~1∑_u~+,C ~1PI_u,and D ~1PI_u and including nonadiabatic couplings.The solution of this set provides the percent contribution of these four states to each of the observed rovibronic level.