Valley-ridge inflection point, potential

Sheppard, A.N., Acevedo, O. Multidimensional exploration of valley-ridge inflection points on potential energy surfaces. J. Am. Chem. Soc. 2009,131, 2530 40. 

Hirsch, M. Quapp, W. Heidrich, D. The set of valley-ridge inflection points on the potential energy surface of water. Phys. Chem. Chem. Phys. 1999, 1, 5291-5299. 

Figure 1 A model potential energy surface illustrating minima, transition structures, second-order saddle points, a valley-ridge inflection point, and reaction paths (Reproduced from Ref, 2a, with permission from World Scientific Publishing)...

---