It is possible for a classical field theory to have two homogeneous stable equilibrium states with different energy densities. In the quantum version of the theory, the state of higher energy density becomes unstable through barrier penetration. In the first paper in this series, it was argued that the relevant quantity to study was a decay probability per unit time per unit volume, Γ/V = Ae-B/ℏ[1+O(ℏ)], and the theory of the coefficient B was given. This paper gives the theory of the coefficient A.