Nudged Elastic Band Method for Molecular Reactions Using Energy-Weighted Springs Combined with Eigenvector Following

• DOI: 10.1021/acs.jctc.1c00462
• Publication Date: 2021-07-18T16:47:50Z
• Authors: Vilhjálmur Ásgeir...; Benedikt Orri Bir...; Ragnar Bjornsson; Ute Becker; Frank Neese; Christoph Riplinger; Hannes Jónsson
• Keywords: Saddle; Benchmark (surveying); Saddle point; Climbing

The climbing image nudged elastic band method (CI-NEB) is used to identify reaction coordinates and find saddle points representing transition states of reactions. It can make efficient use parallel computing as the calculations discretization points, so-called images, be carried out simultaneously. In typical implementations, images are distributed evenly along path by connecting adjacent with equally stiff springs. However, for systems a high degree flexibility, this lead poor resolution near point. By making spring constants increase energy, point improved. To assess performance energy-weighted CI-NEB method, benchmark set 121 molecular analyzed respect input parameters. Energy-weighted springs found greatly improve result in successful location less than thousand energy force evaluations on average (about hundred per image) using same parameter values all Even better obtained stopping calculation before full convergence complete search an eigenvector following starting from image. This combination methods, referred NEB-TS, turns robust highly it reduces number down third, 305. An flexible implementation these methods has been made available ORCA software.