naa a22 4500 528786636 20180924065501.0 cr unu---uuuuu 180924s2018 xx s 000 0 eng 10.3929/ethz-b-000290532 doi 10.1039/c8fd00085a doi (ETHRESEARCH)oai:www.research-collection.ethz.ch:20.500.11850/290532 Ab initio instanton rate theory made efficient using Gaussian process regression [Elektronische Daten] [Gabriel Laude, Danilo Calderini, David P. Tew, Jeremy O. Richardson] Faraday discuss. Open access ethresearch Ab initio instanton rate theory is a computational method for rigorously including tunnelling effects into the calculations of chemical reaction rates based on a potential-energy surface computed on the fly from electronic-structure theory. This approach is necessary to extend conventional transition-state theory into the deep-tunnelling regime, but it is also more computationally expensive as it requires many more ab initio calculations. We propose an approach which uses Gaussian process regression to fit the potential-energy surface locally around the dominant tunnelling pathway. The method can be converged to give the same result as from an on-the-fly ab initio instanton calculation but it requires far fewer electronic-structure calculations. This makes it a practical approach for obtaining accurate rate constants based on high-level electronic-structure methods. We show fast convergence to reproduce benchmark H + CH4 results and evaluate new low-temperature rates of H + C2H6 in full dimensionality at a UCCSD(T)-F12b/cc-pVTZ-F12 level. Creative Commons Attribution 3.0 Unported http://creativecommons.org/licenses/by/3.0 ethresearch Laude Gabriel joint author Calderini Danilo joint author Tew David P. joint author Richardson Jeremy O. joint author Faraday Discussions London : Royal Society of Chemistry (RSC) 1359-6640 http://hdl.handle.net/20.500.11850/290532 text/html WWW-Backlink auf das Repository (Open access) 1 Journal Article ethresearch ETHRESEARCH 856 40 http://hdl.handle.net/20.500.11850/290532 text/html WWW-Backlink auf das Repository (Open access) ETHRESEARCH 700 1- Laude Gabriel joint author ETHRESEARCH 700 1- Calderini Danilo joint author ETHRESEARCH 700 1- Tew David P. joint author ETHRESEARCH 700 1- Richardson Jeremy O. joint author ETHRESEARCH 773 0- Faraday Discussions London : Royal Society of Chemistry (RSC) 1359-6640 BK010053 XK010053 XK010000 ETHRESEARCH ETHRESEARCH ETHRESEARCH Journal Article Open access