Extensive ab initio calculations of static electric properties of molecular ions of general formula RgH(+) (Rg = He, Ne, Ar, Kr, Xe) involving the finite field method and coupled cluster CCSD(T) approach have been done. The relativistic effects were taken into account by Douglas-Kroll-Hess approximation. The numerical stability and reliability of calculated values have been tested using the systematic sequence of Dunning's cc-pVXZ-DK and ANO-RCC-VQZP basis sets. The influence of ZPE and pure vibrational contribution has been discussed. The component alpha(zz) has increasing trend in RgH(+) while the relativistic effect on alpha(zz) leads to a small increase of this molecular parameter. (C) 2009 Published by Elsevier B.V.