Abstract: The reasonable dissociation limit of the ground state(X2П)of SiH radical is attained by employing the molecular reaction dynamics theory.The accurate equilibrium geometry and harmonic frequency of this state are calculated using the coupled-cluster theory QCISD(T) and a very large basis set(cc-PVQZ).The potential energy curve is also calculated over the internuclear separation from 0.10 to 1.71 nm.The equilibrium separation,harmonic frequency and dissociation energy of the vertical excitation energies fro...