TY - JOUR
T1 - Systematic study of structural and thermodynamic properties of HCl(H 2O)n clusters from semiempirical replica exchange simulations
AU - Lin, Wei
AU - Paesani, Francesco
N1 - Copyright:
Copyright 2013 Elsevier B.V., All rights reserved.
PY - 2013/8/15
Y1 - 2013/8/15
N2 - The structural and thermodynamic properties of HCl(H2O) n clusters with n = 4-10 are studied using Born-Oppenheimer replica exchange molecular dynamics simulations with the PM3-MAIS semiempirical Hamiltonian. Independently of the cluster size, the simulations predict that HCl exists in the dissociated form in all low-energy isomers. Different local structures are identified within the clusters due to the presence of the dissociated proton, including Zundel, Eigen, Eigen-like, H7O 3+, and intermediate Zundel-Eigen configurations. As the cluster size increases, several groups of isomers are identified, whose relative stabilities vary as a function of temperature. A detailed analysis of the heat capacity indicates that the melting behavior of HCl(H2O)n clusters is strongly size-dependent. In particular, melting is observed in clusters with n = 7-10 in the temperature range T = 100-150 K. By contrast, melting is not observed in clusters with n = 4-6. Minimum energy structures for HCl(H2O)n clusters with n = 11-15 and n = 21 are also characterized.
AB - The structural and thermodynamic properties of HCl(H2O) n clusters with n = 4-10 are studied using Born-Oppenheimer replica exchange molecular dynamics simulations with the PM3-MAIS semiempirical Hamiltonian. Independently of the cluster size, the simulations predict that HCl exists in the dissociated form in all low-energy isomers. Different local structures are identified within the clusters due to the presence of the dissociated proton, including Zundel, Eigen, Eigen-like, H7O 3+, and intermediate Zundel-Eigen configurations. As the cluster size increases, several groups of isomers are identified, whose relative stabilities vary as a function of temperature. A detailed analysis of the heat capacity indicates that the melting behavior of HCl(H2O)n clusters is strongly size-dependent. In particular, melting is observed in clusters with n = 7-10 in the temperature range T = 100-150 K. By contrast, melting is not observed in clusters with n = 4-6. Minimum energy structures for HCl(H2O)n clusters with n = 11-15 and n = 21 are also characterized.
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U2 - 10.1021/jp400629t
DO - 10.1021/jp400629t
M3 - Article
C2 - 23537473
AN - SCOPUS:84882337122
SN - 1089-5639
VL - 117
SP - 7131
EP - 7141
JO - Journal of Physical Chemistry A
JF - Journal of Physical Chemistry A
IS - 32
ER -