that describe the "tilt" of the CX. When s x and s y are small, the CX is strongly peaked or hourglassshaped, as in Fig. (a). Larger values of either s x or s y correspond to a more sloped CX in either the g or the h direction, respectively, as in Fig. ). Peaked CXs are generally understood to be better funnels, leading to more efficient nonadiabatic transitions. Note also that it is common to minimize the energy along the seam coordinate s JK , maintaining the degeneracy E J (R) = E K (R). This affords the minimum-energy crossing point (MECP) along the conical seam, which is sometimes characterized as "the" CX. Both of the intersection points that are plotted in Fig. are MECPs along a particular conical seam.