The ionization energy (IE) of VCH, the 0 K V-CH/VC-H bond dissociation energies (D(0)s), and the heats of formation at 0 K (Delta H-f0 degrees) and 298 K (Delta H-f298 degrees) for VCH/VCH+ are predicted by the wave function-based CCSDTQ/CBS approach. This composite-coupled cluster method includes full quadruple excitations in conjunction with the approximation to the complete basis set (CBS) limit. The contributions of zero-point vibrational energy, core-valence (CV) correlation, spin-orbit coupling, and scalar relativistic corrections are taken into account. The present calculations show that adiabatic IE(VCH) = 6.785 eV and demonstrate excellent agreement with an IE value of 6.774 7 +/- 0.000 1 eV measured with two-color laser-pulsed field ionization-photoelectron spectroscopy. The CCSDT and MRCI+Q methods which include CV correlations give the best predictions of harmonic frequencies: omega(2) (omega(+)(2)) (bending) = 534 (650) and 564 (641) cm(-1) and the V-CH stretching omega 3 (omega(+)(3)) = 835 (827) and 856 (857) cm(-1) compared with the experimental values. In this work, we offer a streamlined CCSDTQ/CBS approach which shows an error limit (<= 20 meV) matching with previous benchmarking efforts for reliable IE and D-0 predictions for VCH/VCH+ . The CCSDTQ/CBS D-0(V+-CH) - D-0(V-CH) = -0.012 eV and D-0(VC+-H) - D-0 (VC-H) = 0.345 eV are in good accord with the experimentally derived values of -0.028 4 +/- 0.000 1 and 0.355 9 +/- 0.000 1 eV, respectively. The present study has demonstrated that the CCSDTQ/CBS protocol can be readily extended to investigate triatomic molecules containing 3d-metals.