TY - JOUR
T1 - Finding Free-Energy Landmarks of Chemical Reactions
AU - Shiga, Motoyuki
AU - Tuckerman, Mark E.
N1 - Publisher Copyright:
Copyright © 2018 American Chemical Society.
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 -