Reaction Channels of the Potential Energy Surface:
  Application of Newton Trajectories

by 
  MICHAEL HIRSCH &  WOLFGANG QUAPP

 Mathematical Institute,  University of Leipzig, 
 Augustus-Platz,  D-04109 Leipzig,  Germany



abstract:
The reaction path is an important concept of theoretical chemistry.
 We employ the definition of the Newton trajectory (NT).
 An NT follows a curve where the gradient is always a pointer to a fixed
 direction. Usually, a whole family of NTs connects two adjacent 
 stationary points of an index difference of one.
 We will name such a family a reaction channel.  
 The border between two reaction channels is formed by singular NTs
 which cross valley-ridge inflection (VRI) points.
Examples are given with the M"uller-Brown potential,
and the potential energy surfaces of water and formaldehyde.