Systematic study of structural and thermodynamic properties of HCl(H 2O)n clusters from semiempirical replica exchange simulations

Wei Lin, Francesco Paesani

Research output: Contribution to journalArticlepeer-review

14 Scopus citations

Abstract

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.

Original languageEnglish (US)
Pages (from-to)7131-7141
Number of pages11
JournalJournal of Physical Chemistry A
Volume117
Issue number32
DOIs
StatePublished - Aug 15 2013

Fingerprint Dive into the research topics of 'Systematic study of structural and thermodynamic properties of HCl(H <sub>2</sub>O)<sub>n</sub> clusters from semiempirical replica exchange simulations'. Together they form a unique fingerprint.

Cite this