EStokTP: Electronic Structure to Temperature- and Pressure-Dependent Rate Constants—A Code for Automatically Predicting the Thermal Kinetics of Reactions

• DOI: 10.1021/acs.jctc.8b00701
• Publication Date: 2018-12-21T23:06:42Z
• Authors: C. Cavallotti; M. Pelucchi; Y. Georgievskii; S. J. Klippenstein
• Keywords: Solver; Hessian matrix

A priori rate predictions for gas phase reactions have undergone a gradual but dramatic transformation, with current often rivaling the accuracy of best available experimental data. The utility such kinetic would be greatly magnified if they could more readily implemented large numbers systems. Here, we report development new computational environment, namely, EStokTP, that reduces human effort involved in prediction single channel essentially to specification methodology employed. code can also used obtain all necessary master equation building blocks complex reactions. In general, constants involves two steps, first consisting set electronic structure calculations and second application some form solver, as transition state theory (TST)-based solver. EStokTP provides fully integrated treatment both steps through calls external codes perform then calculations. It focuses on generating, extracting, organizing structural properties from sequence codes, robust automatic failure recovery options limit intervention. implements one or multidimensional hindered rotor treatments internal torsional modes (with automated projection Hessian optional vibrationally adiabatic corrections), Eckart tunneling models (such small curvature theory), variational (based intrinsic reaction coordinate following). This focus implementation high-level TST methods allows high studies sets reactions, illustrated here sample few hundred At present, following types are EStokTP: abstraction, addition, isomerization, beta-decomposition. Preliminary protocols treating barrierless multiple-well and/or multiple-channel potential energy surfaces illustrated.