CCSD(T) and DFT-PBE calculations with the Pol and HyPol basis sets have been performed in the series formaldehyde, formamide and urea to obtain accurate gas and solution phase molecular structures, rotational barriers, vibrational and electronic (hyper)polarizabilities in the static and dynamic (omega = 0.04282 a.u.) regime. Comparison with available experimental data shows good agreement for polarizabilities and second hyperpolarizability of urea, while beta(SHG) of urea is strongly underestimated because of overerestimation of solvent effects. (c) 2005 Elsevier B.V. All rights reserved.