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

By means of ab initio calculations with different basis sets, from a m inimum STO-3G basis set up to a 6-31G basis set, both with and withou t inclusion of electron correlation, the energies, geometries, rotatio nal constants, and dipole moments of the 18 hydrogenated derivatives o f hydrogen cyanide (HCN) and cyanoacetylene (HC3N) have been calculate d. The theoretical predictions should prove useful for laboratory and astronomical studies of these species. Some of these molecules have al ready been discovered in the interstellar medium while others are as y et undetected there, although their presence is probable. The rotation al constants herein provided could help in the detection of these in t he interstellar medium.