Accurate ab initio SCF and MP2 quartic property (hyper)surfaces have been computed for the energy, quadrupole moment, Theta, polarizability, alpha, and polarizability anisotropy, Delta alpha, of acetylene (HCCH) with the properties expanded in a Taylor series of the dimensionless normal coordinates, qi, about the potential energy minimum. Applying the contact transformation expressions for the expectation value of a property in an arbitrary rotational vibrational state, we obtain both zero-point vibrational corrections (ZPVCs) to the properties and predictions ofthe properties inexcited rotational-vibrational states. A numerical least-squares method was utilized for the calculation of the required derivatives. We have also computed accurate electrical properties at the experimental re geometry in order to provide definitive estimates of Theta, alpha and Delta alpha for acetylene that incorporate both vibrational and rotational effects. A wide range of electron-correlation methods were utilized for this purpose including QCISD(T), BD and BD(T), coupled with a range of large augmented triple-zeta basis sets. Special attention was paid to the quadrupole moment, Theta, as there has been substantial interest and controversy in the experimental determination of this quantity. Where possible we have critically compared theory and experiment, the outcome highlighting the utility of the present method and the general necessity for the inclusion of vibrational corrections with accurate theoretical predictions of electrical properties. [ABSTRACT FROM AUTHOR]