Bond distances, vibrational frequencies and dipole moments of the RhX (X = C, N, O, F, P and Cl) molecules were studied by density functional theory (DFT) methods. For all molecules under consideration, spectroscopic properties are computed using various functionals. This study is the first systematic ab initio investigation of the RhX molecules and in those cases where comparison with experimental data can be made, good quantitative agreement is achieved when using the BP86 functional. (c) 2006 Elsevier B.V. All rights reserved.