TY - JOUR
T1 - Finding Free-Energy Landmarks of Chemical Reactions
AU - Shiga, Motoyuki
AU - Tuckerman, Mark E.
N1 - Funding Information:
M.E.T. acknowledges support from the National Science Foundation Grant No. CHE-1565980. M.S. acknowledges support from JSPS KAKENHI Grant Numbers 16K05675 and 18H05519. This work was initiated while M.E.T. was an International Research Fellow of the Japan Society for the Promotion of Science (JSPS). Both M.E.T. and M.S. gratefully acknowledge the JSPS for the fellowship that made conceiving this work possible.
PY - 2018/11/1
Y1 - 2018/11/1
N2 - We propose a novel approach to search for free-energy landmarks, i.e., minima and the saddle points, of chemical reactions in an automated manner using a combination of steepest descent and gentlest ascent methods. A numerical approach is suggested to improve the sampling efficiency of the second derivatives of the free-energy surface, which is required in the gentlest ascent method. This technique opens a way to identify free-energy landmarks of bond-breaking/creating processes in which the underlying potential energy surface is described using on-the-fly electronic structure calculations. As demonstrations of the approach, we present applications to the ring-opening of cis-1,2-dimethylbenzocyclobutene using the semiempirical PM7 method, focusing on the temperature dependence of the paths and barrier of the reaction, and we study an SN2 reaction in aqueous solution using a semiempirical QM/MM approach combining PM7 with the TIP3P water model.
AB - We propose a novel approach to search for free-energy landmarks, i.e., minima and the saddle points, of chemical reactions in an automated manner using a combination of steepest descent and gentlest ascent methods. A numerical approach is suggested to improve the sampling efficiency of the second derivatives of the free-energy surface, which is required in the gentlest ascent method. This technique opens a way to identify free-energy landmarks of bond-breaking/creating processes in which the underlying potential energy surface is described using on-the-fly electronic structure calculations. As demonstrations of the approach, we present applications to the ring-opening of cis-1,2-dimethylbenzocyclobutene using the semiempirical PM7 method, focusing on the temperature dependence of the paths and barrier of the reaction, and we study an SN2 reaction in aqueous solution using a semiempirical QM/MM approach combining PM7 with the TIP3P water model.
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U2 - 10.1021/acs.jpclett.8b01958
DO - 10.1021/acs.jpclett.8b01958
M3 - Article
C2 - 30286601
AN - SCOPUS:85055110422
SN - 1948-7185
VL - 9
SP - 6207
EP - 6214
JO - Journal of Physical Chemistry Letters
JF - Journal of Physical Chemistry Letters
IS - 21
ER -