W.Quapp  and  J.M.Bofill

 Locating Saddle Points of any Index on Potential Energy Surfaces 
 by the Generalized Gentlest Ascent Dynamics

2014 submitted to TCA 

Abstract:
The system of ordinary differential equations for the method of the gentlest ascent
dynamics (GAD) is used to determine the saddle points of the PES of some molecules.
The method has been proposed earlier by W.E and X.Zhou [Nonlinearity 24, 1831 (2011)].
 
We additionally use the metric of curvilinear internal coordinates.
By a number of examples we explain the possibilities of a GAD curve: 
it can find the transition state of interest by a gentlest ascent, directly
or indirectly, or not.

We further propose generalized GAD formulas for the search of saddle points
of a higher index.

Discussed examples are the Rastrigin and Ackley surfaces,  LJ_7 cluster, 
and the Radicales H_3CO, NH_5  and CH_5^-.


Further reference:

Bofill JM, Quapp W, Caballero M,  Chem Phys Lett 583, 203-208 (2013)