Implementation and performance of the artificial force induced reaction method in the GRRM17 program

Abstract

This article reports implementation and performance of the artificial force induced reaction (AFIR) method in the upcoming 2017 version of GRRM program (GRRM17). The AFIR method, which is one of automated reaction path search methods, induces geometrical deformations in a system by pushing or pulling fragments defined in the system by an artificial force. In GRRM17, three different algorithms, that is, multicomponent algorithm (MC‐AFIR), single‐component algorithm (SC‐AFIR), and double‐sphere algorithm (DS‐AFIR), are available, where the MC‐AFIR was the only algorithm which has been available in the previous 2014 version. The MC‐AFIR does automated sampling of reaction pathways between two or more reactant molecules. The SC‐AFIR performs automated generation of global or semiglobal reaction path network. The DS‐AFIR finds a single path between given two structures. Exploration of minimum energy structures within the hypersurface in which two different electronic states degenerate, and an interface with the quantum mechanics/molecular mechanics method, are also described. A code termed SAFIRE will also be available, as a visualization software for complicated reaction path networks. © 2017 The Authors. Journal of Computational Chemistry Published by Wiley Periodicals, Inc.

Excited‐State Reactivity of [Mn(im)(CO)3(phen)]+: A Structural Exploration

“…Connections of these MECIs on the S 1 and S 2 surfaces were studied by meta‐intrinsic reaction coordinate (meta‐IRC) calculations starting from these MECIs on each of the two surfaces, where meta‐IRC corresponds to mass‐weighted steepest descent path computed from nonstationary point . TS structures for paths leading to these MECIs on S 2 as well as those leading to dissociation channels on S 1 were searched using the double‐sphere AFIR (DS‐AFIR) algorithm . In these calculations, geometrical displacements were made by the GRRM program using gradients computed by the Gaussian 16 program…”

Automated reaction path searches for spin‐forbidden reactions

“…From these potential energy surface characterizations, one can qualitatively understand the mechanisms of a chemical reaction . Recently, automated reaction path searches using various computational algorithms are becoming useful tools, which enable identification of energetically important reaction pathways on the potential energy surface directly obtained from quantum chemistry calculations . For example, Maeda and Ohno have developed a powerful and automated scaled hypersphere search algorithm implemented in the GRRM (Global Reaction Route Mapping) computer code, which has been interfaced with various quantum chemistry software packages.…”

“…More recently, it should be mentioned that efficient reaction path search algorithms on the basis of string method, including the single‐ended growing string method and freezing string method, have also been developed . These newly developed algorithms have been benchmarked and applied to a large number of chemical reaction systems to understand the detailed mechanisms, kinetics and dynamics . According to the most recent computational work, the string methods are found to be more efficient than AFIR for atmospheric and combustion reaction systems …”

Designing the Backbone of Hexasilabenzene Derivatives with a High Unimolecular Kinetic Stability

“…By applying the AFIR method to obtained MINs one after another, a network of reaction paths can be obtained. Details of the AFIR method are given in our previous papers …”

“…In this study, we have designed a kinetically stable hexasilabenene derivative with a planar, monocyclic Si 6 backbone. The key methodologies to achieve the design are the artificial force induced reaction (AFIR) method combined with the rate constant matrix contraction (RCMC) method . Using these methods, we evaluated unimolecular lifetimes of hexasilabenzene (Si 6 H 6 ), a sila‐substituted dicyclic compound decasilanaphthalene (Si 10 H 8 ), and lithium‐substituted hexasilabenzene (Si 6 Li 6 ).…”