where u(x) is the restraining potential applied to the degree of freedom x. These degrees of freedom are defined in Figure . The second term in Equation integrates over the position of anchor atom A with respect to the receptor coordinates, and does not depend on anchor atoms B and C. The third term integrates over the orientation of the ligand with respect to the receptor. Hence, Boresch restraints can be used to restrain only the position of the anchor point A with respect to the receptor, by setting u(θ B ), u(ϕ B ), and u(ϕ C ) to 0.