where it is assumed that the integrals in eq. 10 and 11 can be extended to ±∞, and that sin θ A and sin θ B can be treated as the constants sin θ A,0 and sin θ B,0 , and moved out of the integrals. Both assumptions are strongly justified for appropriately selected restraints which are not subject to instabilities. Taking into account eq. 13-14, the angular correction free energy of eq. 7 can be expressed as: