 In a traditional implementation, the point with the highest energy is used for subsequent refinement in a local search.There are many variations on the NEB (nudged elastic band) method, such including the climbing image NEB, in which the point with the highest energy is pushed upwards during the optimization procedure so as to (hopefully) give a geometry which is even closer to that of the transition state.The string method uses splines connecting the points, , to measure and enforce distance constraints between the points and to calculate the tangent at each point.