Volume II/20 provides critically evaluated data on free molecules, obtained from infrared spectroscopy and related experimental and theoretical investigations. The volume is divided into four subvolumes, , , , . The present subvolume II/20 b1 contains the general introduction and data for the linear triatomic molecules BClH+(HBCl+) ... COSe(OCSe), critically evaluated from the original literature up to 1994. Subvolume b2 containing data for CO2(OCO), subvolume b3 containing data for CS2(SCS) ... N3(NNN), and further subvolumes are in preparation.weiterlesen