Chain methods

The chain methods are designed to optimize the entire path between reactants and products. In a paper by Henkelman et al. the different chain methods are reviewed [142]. The most popular techniques are based on the progressive optimization of a chain of points that connect reactants and products. Since they are designed to be applied in big systems the usage of a big Hessian matrix is always avoided. This makes that the efficiency is relatively low. In some cases they have been applied to biomolecular systems such as the Nudged Elastic Band (NEB) [143,144,145], the Conjugate Peak Refinement [146,147] and the Replica Path [148].