The essential features of the potential energy surface for the thermal decomposition of silane have been calculated with extended basis sets, augmented by correlation corrections. It is predicted that the transition state for the molecular elimination lies 56.9 kcaljmol above silane. For the reverse reaction, the transition state is less than 2 kcal/mol above the separated fragments, silylene and molecular hydrogen, but 4.8 kcal/mol above a long-range potential well. In the latter, the silylene-H2 separation is 1.78 A, and the bond in H2 has stretched by more than 0.05 A. This indicates a significant electronic interaction between the fragments even at the large fragment separation. The depth of the well is less than I kcaljmol at the SCF level of theory, but it increases substantially when correlation is introduced into the wave function. Since the calculated SiH bond energy is 22 kcalfmollarger than the activation energy for the molecular elimination, the homolytic cleavage of silane to form silyl radical is not expected to be an important process in the low-energy pyrolysis of silane.