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ID 57460
フルテキストURL
著者
Sumi, Tomonari Department of Chemistry, Faculty of Science, Okayama University ORCID Kaken ID publons researchmap
Maruyama, Yutaka Co-Design Team, Exascale Computing Project, RIKEN Advanced Institute for Computational Science
Mitsutake, Ayori Co-Design Team, Exascale Computing Project, RIKEN Advanced Institute for Computational Science
Koga, Kenichiro Department of Chemistry, Faculty of Science, Okayama University ORCID Kaken ID publons researchmap
抄録
In the conventional classical density functional theory (DFT) for simple fluids, an ideal gas is usually chosen as the reference system because there is a one-to-one correspondence between the external field and the density distribution function, and the exact intrinsic free-energy functional is available for the ideal gas. In this case, the second-order density functional Taylor series expansion of the excess intrinsic free-energy functional provides the hypernetted-chain (HNC) approximation. Recently, it has been shown that the HNC approximation significantly overestimates the solvation free energy (SFE) for an infinitely dilute Lennard-Jones (LJ) solution, especially when the solute particles are several times larger than the solvent particles [T. Miyata and J. Thapa, Chem. Phys. Lett. 604, 122 (2014)]. In the present study, we propose a reference-modified density functional theory as a systematic approach to improve the SFE functional as well as the pair distribution functions. The second-order density functional Taylor series expansion for the excess part of the intrinsic free-energy functional in which a hard-sphere fluid is introduced as the reference system instead of an ideal gas is applied to the LJ pure and infinitely dilute solution systems and is proved to remarkably improve the drawbacks of the HNC approximation. Furthermore, the third-order density functional expansion approximation in which a factorization approximation is applied to the triplet direct correlation function is examined for the LJ systems. We also show that the third-order contribution can yield further refinements for both the pair distribution function and the excess chemical potential for the pure LJ liquids.
発行日
2016-06-10
出版物タイトル
Journal of Chemical Physics
144巻
22号
出版者
American Institute of Physics
開始ページ
224104
ISSN
00219606
NCID
AA00694991
資料タイプ
学術雑誌論文
言語
English
OAI-PMH Set
岡山大学
論文のバージョン
author
PubMed ID
DOI
Web of Science KeyUT
関連URL
isVersionOf https://doi.org/10.1063/1.4953191
助成機関名
文部科学省