---
OA_place: publisher
OA_type: hybrid
PlanS_conform: '1'
_id: '22773'
abstract:
- lang: eng
  text: An important quantity in liquid state theory is the radial distribution function
    g(r). It can be calculated within the framework of classical density functional
    theory in two very distinct ways. In the test-particle route, one fixes a single
    fluid particle, turning it into an external potential in which the inhomogeneous
    structure of the fluid is calculated by minimizing the functional. The second
    route to g(r) in density functional theory employs the Ornstein–Zernike equation
    and the pair direct correlation function, that can be obtained from the second
    functional derivatives of the excess (over the ideal gas) free energy functional.
    Since typically an approximate excess free energy functional is employed, the
    test-particle route, which requires only one functional derivative, is more accurate
    than the Ornstein–Zernike route. Here we study a two-dimensional core-shoulder
    particle system and find that in some circumstances the results from the Ornstein–Zernike
    route can be comparable in accuracy to the test-particle results for r > σ, the
    core diameter. We also examine in detail the asymptotic r → ∞ decay of g(r), finding
    a variety of possible decay wavelengths at different state points and state points
    where there is a crossover from one wavelength to a very different one. This behavior
    is a signature pointing to the rich phase behavior of the incipient solid phases.
acknowledgement: We are grateful to Florian Sanmüller and Matthias Schmidt for valuable
  comments on the manuscript and helpful discussions. The simulation results presented
  here were enabled via a generous allocation of CPU time by the Austrian Scientific
  Computing (ASC) under Project No. 71263. The authors thank Katrin Muck for her guidance
  related to the use of HPC. A.J.A. gratefully acknowledges support from the EPSRC
  under Grant No. EP/P015689/1. This research was funded in part by the Austrian Science
  Fund (FWF) under project no. PIN8759524 with Grant-DOI 10.55776/PIN8759524, gratefully
  acknowledged by GK.
article_processing_charge: Yes (in subscription journal)
article_type: original
arxiv: 1
author:
- first_name: Michael
  full_name: Wassermair, Michael
  id: 23d132c4-4e98-11ef-b275-9e8d4cd8c917
  last_name: Wassermair
  orcid: 0009-0003-6339-4051
- first_name: Gerhard
  full_name: Kahl, Gerhard
  last_name: Kahl
- first_name: Andrew J.
  full_name: Archer, Andrew J.
  last_name: Archer
- first_name: Roland
  full_name: Roth, Roland
  last_name: Roth
citation:
  ama: Wassermair M, Kahl G, Archer AJ, Roth R. Radial distribution function in a
    two-dimensional core-shoulder particle system. <i>Journal of Physical Chemistry
    B</i>. 2026;130(33):8514-8526. doi:<a href="https://doi.org/10.1021/acs.jpcb.6c00653">10.1021/acs.jpcb.6c00653</a>
  apa: Wassermair, M., Kahl, G., Archer, A. J., &#38; Roth, R. (2026). Radial distribution
    function in a two-dimensional core-shoulder particle system. <i>Journal of Physical
    Chemistry B</i>. American Chemical Society. <a href="https://doi.org/10.1021/acs.jpcb.6c00653">https://doi.org/10.1021/acs.jpcb.6c00653</a>
  chicago: Wassermair, Michael, Gerhard Kahl, Andrew J. Archer, and Roland Roth. “Radial
    Distribution Function in a Two-Dimensional Core-Shoulder Particle System.” <i>Journal
    of Physical Chemistry B</i>. American Chemical Society, 2026. <a href="https://doi.org/10.1021/acs.jpcb.6c00653">https://doi.org/10.1021/acs.jpcb.6c00653</a>.
  ieee: M. Wassermair, G. Kahl, A. J. Archer, and R. Roth, “Radial distribution function
    in a two-dimensional core-shoulder particle system,” <i>Journal of Physical Chemistry
    B</i>, vol. 130, no. 33. American Chemical Society, pp. 8514–8526, 2026.
  ista: Wassermair M, Kahl G, Archer AJ, Roth R. 2026. Radial distribution function
    in a two-dimensional core-shoulder particle system. Journal of Physical Chemistry
    B. 130(33), 8514–8526.
  mla: Wassermair, Michael, et al. “Radial Distribution Function in a Two-Dimensional
    Core-Shoulder Particle System.” <i>Journal of Physical Chemistry B</i>, vol. 130,
    no. 33, American Chemical Society, 2026, pp. 8514–26, doi:<a href="https://doi.org/10.1021/acs.jpcb.6c00653">10.1021/acs.jpcb.6c00653</a>.
  short: M. Wassermair, G. Kahl, A.J. Archer, R. Roth, Journal of Physical Chemistry
    B 130 (2026) 8514–8526.
corr_author: '1'
das_tickbox: '0'
date_created: 2026-08-30T22:01:44Z
date_published: 2026-08-20T00:00:00Z
date_updated: 2026-09-09T11:11:12Z
day: '20'
ddc:
- '530'
- '540'
department:
- _id: AnSa
doi: 10.1021/acs.jpcb.6c00653
external_id:
  arxiv:
  - '2603.24537'
  pmid:
  - '42622279'
file:
- access_level: open_access
  checksum: 67313d68ab13b553a38e8b4bf99983d2
  content_type: application/pdf
  creator: dernst
  date_created: 2026-09-09T11:05:02Z
  date_updated: 2026-09-09T11:05:02Z
  file_id: '22871'
  file_name: 2026_JourPhysicChemistryB_Wassermair.pdf
  file_size: 7472078
  relation: main_file
  success: 1
file_date_updated: 2026-09-09T11:05:02Z
fulldoi: https://doi.org/10.1021/acs.jpcb.6c00653
has_accepted_license: '1'
intvolume: '       130'
issue: '33'
language:
- iso: eng
month: '08'
oa: 1
oa_version: Published Version
page: 8514-8526
pmid: 1
publication: Journal of Physical Chemistry B
publication_identifier:
  eissn:
  - 1520-5207
  issn:
  - 1520-6106
publication_status: published
publisher: American Chemical Society
quality_controlled: '1'
researchdata_availability: no
scopus_import: '1'
status: public
supplementarymaterial: yes
title: Radial distribution function in a two-dimensional core-shoulder particle system
tmp:
  image: /images/cc_by.png
  legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
  name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
  short: CC BY (4.0)
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 130
year: '2026'
...