Free-energy calculation of structure-H hydrates

Yamato Okano, Kenji Yasuoka

Research output: Contribution to journalArticle

43 Citations (Scopus)

Abstract

A molecular-dynamics (MD) simulation of structure-H hydrates was performed under constant pressure and temperature with 6120 TIP4P water molecules, 900 OPLS-UA methane molecules, and 180 large molecular guest substance (LMGS) molecules. The LMGS molecules were represented in the form of a one-site Lennard-Jones (LJ) model using the LJ parameters δ and ε. In order to clarify the thermodynamic stability of structure-H hydrates, we calculated the free-energy difference, changing on the δ and ε only of the LMGS molecules. In this simulation, stable crystals of structure-H hydrates and a minimum value of ΔG were obtained at δ∼6.2 Å and large values of ε. All simulations were performed using the special-purpose computer hardware MDGRAPE-2.

Original languageEnglish
Article number024510
JournalJournal of Chemical Physics
Volume124
Issue number2
DOIs
Publication statusPublished - 2006

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Hydrates
hydrates
Free energy
free energy
Molecules
molecules
simulation
Methane
Computer hardware
Molecular dynamics
hardware
Thermodynamic stability
methane
molecular dynamics
thermodynamics
Crystals
Water
Computer simulation
water
crystals

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics

Cite this

Free-energy calculation of structure-H hydrates. / Okano, Yamato; Yasuoka, Kenji.

In: Journal of Chemical Physics, Vol. 124, No. 2, 024510, 2006.

Research output: Contribution to journalArticle

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