The excited states of Sr+CO: photofragmentation spectra and ab initio calculations

The first absorption band in the photofragmentation spectroscopy of Sr+CO, is recorded in the energy region between 15 600 and 16 200 cm−1. The spectrum is characterized by a sharp peak between two zones with broad peaks. In contrast to this, the second absorption band observed in the energy interval of 19 000–23 000 cm−1 shows a regular vibrational structure accompanied by a low intensity shoulder which covers the energy up to the dissociation. Electronic multi-reference configuration interaction calculations in the 2-D nuclear configuration space with the CO bond frozen provide a qualitative explanation of the spectra.