With the advent of modern instruments and theories, a considerable amount of spectroscopic information has been collected on molecules during this last decade. The infrared, in particular, has seen extraordinary activity. Using Fourier transform interferometers and infrared lasers, accurate data have been measured, often with extreme sensitivity. These data have also been analyzed and accurate molecular parameters determined. Volume II/20, "Molecular Constants mostly from Infrared Spectroscopy", is a recent Landolt-Bornstein publication series. It is made up of several subvolumes (A, B, C, D) with comprehensive compilation of critically evaluated molecular constants of diatomic (A), linear triatomic (B), other triatomic (C) and other polyatomic (D) molecules. The first subvolume, II/20B1, published in 1995, deals with 39 linear triatomic molecules and their + + isotopic species, from BClH (HBCl ) to COSe (OCSe), given in the alphabetical order of their Hill's formulas as indicated below: + + 1 BClH (HBCl ) 9 BeF2 (FBeF) 17 CCaN (CaNC) 25 CHN (HNC) 33 CMgN (MgCN) + + + + 2 BClH (BClH ) 10 CBaN (BaCN) 18 CClN (ClCN) 26 CHO (HCO ) 34 CMgN (MgNC) + + + + ? ?
3 BClO (OBCl) 11 CBaN (BaNC) 19 CClN (ClCN) 27 CHO (HOC) 35 CNO (NCO ) + + 4 BFH (HBF ) 12 CBeN (BeCN) 20 CClP (ClCP) 28 CHP (HCP) 36 CNS (NCS) + + ? ? 5 BFO (FBO) 13 CBeN (BeNC) 21 CFN (FCN) 29 CHS (HCS) 37 CNS (NCS )