Structure and Analysis of Some Bands of the B→X and D→X Systems of PbO

The (1,0) and (1,1) bands of the B→X and (0,1) and (0,2) bands of the D→X systems have been photographed in the second and third orders, respectively, of a 10.6 meter concave grating spectrograph and the rotational structures of these bands have been analysed. The rotational constants for the most abundant isotopic molecule Pb208 O16 are derived as follows: In addition, several perturbations observed in the v′ = 1 level of the B state and v′ = 0 level of the D state have been studied. With the help of the Schmid and Gerö relation and from the appearance of the perturbed structure, it has been concluded that the perturbing statesh have Ω = 1 and their rotational constants are estimated to be 0,2595 cm−1 and 0.2683 crn−1, respectively.