“…16 It is worth noticing at this point that a D 0 value larger by 5 kcal/mol based on a Birge-Sponer extrapolation of the vibrational levels of the A 1 state had been already reported. 17 This 5 kcal/mol difference was attributed to a maximum in the potential curve of that A 1 state, considering the systematic and uniform discrepancies found in a series of group IIIA monofluorides. 16 In a microwave study, Lovas and Johnson 18 observed direct rotational transitions in the ground vibrational state of 10,11 BF leading to improved ground state constants.…”