Improved initial guess for minimum energy path calculations
A method is presented for generating a good initial guess of a transition path between given initial and final states of a system without evaluation of the energy. An objective function surface is constructed using an interpolation of pairwise distances at each discretization point along the path and the nudged elastic band method then used to find an optimal path on this image dependent pair potential (IDPP) surface. This provides an initial path for the more computationally intensive calculations of a minimum energy path on an energy surface obtained, for example, by ab initio or density functional theory. The optimal path on the IDPP surface is significantly closer to a minimum energy path than a linear interpolation of the Cartesian coordinates and, therefore, reduces the number of iterations needed to reach convergence and averts divergence in the electronic structure calculations when atoms are brought too close to each other in the initial path. The method is illustrated with three examples: (1) rotation of a methyl group in an ethane molecule, (2) an exchange of atoms in an island on a crystal surface, and (3) an exchange of two Siatoms in amorphous silicon. In all three cases, the computational effort inmore »
 Authors:

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 QuantumWise A/S, Lersø Parkallé 107, DK2100 Copenhagen (Denmark)
 (Iceland)
 Science Institute and Faculty of Physical Sciences, University of Iceland VRIII, 107 Reykjavík (Iceland)
 (Switzerland)
 (Finland)
 Publication Date:
 OSTI Identifier:
 22304228
 Resource Type:
 Journal Article
 Resource Relation:
 Journal Name: Journal of Chemical Physics; Journal Volume: 140; Journal Issue: 21; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
 Country of Publication:
 United States
 Language:
 English
 Subject:
 37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ATOMS; CARTESIAN COORDINATES; CRYSTALS; DENSITY FUNCTIONAL METHOD; ELECTRONIC STRUCTURE; ETHANE; EVALUATION; INTERPOLATION; MOLECULES; SILICON; SURFACES