Rare Events, Transition Pathways and Reaction Rates 
Introduction 
ZeroTemperature String Method 
FiniteTemperature String Method 
Modified String Method 
Reference 
Minimal Energy Path 
Dynamics of String 
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Consider two local minima A and B on the
multidimensional potential energy landscape. A can be taken as the initial
state (in the configuration space) and B be the final state (the algorithm actually
works fine as long as B is on the other side of the line dividing the two basins).
Let be the potential which characterizes
the PES and be a path in
configuration space that connects A and B. This path is parameterized by which can be the
position of the system in the multidimentional as is diffusion PES or size of loop for
a nucleation process. The unit tangent vector is denote by
.
is a
minimal energy path (MEP)
if at each point on the path the force perpendicular to the path is zero. This means i.e.
Here
denotes projection to the hyperplane normal to .
