TY - JOUR T1 - Optimization-Based String Method for Finding Minimum Energy Path JO - Communications in Computational Physics VL - 2 SP - 265 EP - 275 PY - 2014 DA - 2014/08 SN - 14 DO - http://doi.org/10.4208/cicp.220212.030812a UR - https://global-sci.org/intro/article_detail/cicp/7159.html KW - AB -

We present an efficient algorithm for calculating the minimum energy path (MEP) and energy barriers between local minima on a multidimensional potential energy surface (PES). Such paths play a central role in the understanding of transition pathways between metastable states. Our method relies on the original formulation of the string method [Phys. Rev. B, 66, 052301 (2002)], i.e. to evolve a smooth curve along a direction normal to the curve. The algorithm works by performing minimization steps on hyperplanes normal to the curve. Therefore the problem of finding MEP on the PES is remodeled as a set of constrained minimization problems. This provides the flexibility of using minimization algorithms faster than the steepest descent method used in the simplified string method [J. Chem. Phys., 126(16), 164103 (2007)]. At the same time, it provides a more direct analog of the finite temperature string method. The applicability of the algorithm is demonstrated using various examples.