Using a semiclassical model that treats the phonons and electrons of a metal quantally within a second quantization formalism and the dynamics of the incoming molecule classically, we have calculated the dissociative sticking and energy accommodation as a function of band structure for the electron-hole pair excitation. It is shown that the electronic band structure has some influence on the reactivity, such that the inclusion of this aspect makes the 111 surface more reactive than the 100 surface-in agreement with experimental findings.