CALCULATED ROTATIONAL-CONSTANTS OF INTERSTELLAR SPECIES - HYDROGENATED DERIVATIVES OF HCN AND HC3N

By means of ab initio calculations with different basis sets, from a minimum STO-3G basis set up to a 6-31G* basis set, both with and without inclusion of electron correlation, the energies, geometries, rotational constants, and dipole moments of the 18 hydrogenated derivatives of hydrogen cyanide (HCN) and cyanoacetylene (HC3N) have been calculated. The theoretical predictions should prove useful for laboratory and astronomical studies of these species. Some of these molecules have already been discovered in the interstellar medium while others are as yet undetected there, although their presence is probable. The rotational constants herein provided could help in the detection of these in the interstellar medium.