The EXP pair-potential system. III. Thermodynamic phase diagram

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

Resumé

This paper determines the thermodynamic phase diagram of the EXP system of particles interacting by the purely repulsive exponential pair
potential. The solid phase is face-centered cubic (fcc) at low densities and pressures. At higher densities and pressures, the solid phase is bodycentered cubic (bcc) with a re-entrant liquid phase at the highest pressures simulated. The investigation first identifies the phase diagram at
zero temperature at which the following four crystal structures are considered: fcc, bcc, hexagonal close packed, and cubic diamond. There is a
T = 0 phase transition at pressure 2.651 × 10−3 with the thermodynamically stable structure being fcc below and bcc above this pressure. The
densities of the two crystal structures at the phase transition are 1.7469 × 10−2
(fcc) and 1.7471 × 10−2
(bcc). At finite temperatures, the fcc–
bcc, fcc-liquid, and bcc-liquid coexistence lines are determined by numerical integration of the Clausius–Clapeyron equation and validated
by interface-pinning simulations at selected state points. The bcc-fcc phase transition is a weak first-order transition. The liquid-fcc–bcc triple
point, which is determined by the interface-pinning method, has temperature 5.9 × 10−5
and pressure 2.5 × 10−6
; the triple-point densities
are 1.556 × 10−3
(liquid), 1.583 × 10−3
(bcc), and 1.587 × 10−3
(fcc).
OriginalsprogEngelsk
Artikelnummer174501
TidsskriftJournal of Chemical Physics
Vol/bind2019
Udgave nummer150
Antal sider9
ISSN0021-9606
DOI
StatusUdgivet - 3 maj 2019

Citer dette

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title = "The EXP pair-potential system. III. Thermodynamic phase diagram",
abstract = "This paper determines the thermodynamic phase diagram of the EXP system of particles interacting by the purely repulsive exponential pair potential. The solid phase is face-centered cubic (fcc) at low densities and pressures. At higher densities and pressures, the solid phase is body-centered cubic (bcc) with a re-entrant liquid phase at the highest pressures simulated. The investigation first identifies the phase diagram at zero temperature at which the following four crystal structures are considered: fcc, bcc, hexagonal close packed, and cubic diamond. There is a T = 0 phase transition at pressure 2.651 × 10−3 with the thermodynamically stable structure being fcc below and bcc above this pressure. The densities of the two crystal structures at the phase transition are 1.7469 × 10−2 (fcc) and 1.7471 × 10−2 (bcc). At finite temperatures, the fcc–bcc, fcc-liquid, and bcc-liquid coexistence lines are determined by numerical integration of the Clausius–Clapeyron equation and validated by interface-pinning simulations at selected state points. The bcc-fcc phase transition is a weak first-order transition. The liquid-fcc–bcc triple point, which is determined by the interface-pinning method, has temperature 5.9 × 10−5 and pressure 2.5 × 10−6; the triple-point densities are 1.556 × 10−3 (liquid), 1.583 × 10−3 (bcc), and 1.587 × 10−3 (fcc).",
author = "Pedersen, {Ulf R{\o}rb{\ae}k} and Bacher, {Andreas Kvist} and Thomas Schr{\o}der and Jeppe Dyre",
year = "2019",
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volume = "2019",
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The EXP pair-potential system. III. Thermodynamic phase diagram. / Pedersen, Ulf Rørbæk; Bacher, Andreas Kvist; Schrøder, Thomas; Dyre, Jeppe.

I: Journal of Chemical Physics, Bind 2019, Nr. 150, 174501, 03.05.2019.

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

TY - JOUR

T1 - The EXP pair-potential system. III. Thermodynamic phase diagram

AU - Pedersen, Ulf Rørbæk

AU - Bacher, Andreas Kvist

AU - Schrøder, Thomas

AU - Dyre, Jeppe

PY - 2019/5/3

Y1 - 2019/5/3

N2 - This paper determines the thermodynamic phase diagram of the EXP system of particles interacting by the purely repulsive exponential pair potential. The solid phase is face-centered cubic (fcc) at low densities and pressures. At higher densities and pressures, the solid phase is body-centered cubic (bcc) with a re-entrant liquid phase at the highest pressures simulated. The investigation first identifies the phase diagram at zero temperature at which the following four crystal structures are considered: fcc, bcc, hexagonal close packed, and cubic diamond. There is a T = 0 phase transition at pressure 2.651 × 10−3 with the thermodynamically stable structure being fcc below and bcc above this pressure. The densities of the two crystal structures at the phase transition are 1.7469 × 10−2 (fcc) and 1.7471 × 10−2 (bcc). At finite temperatures, the fcc–bcc, fcc-liquid, and bcc-liquid coexistence lines are determined by numerical integration of the Clausius–Clapeyron equation and validated by interface-pinning simulations at selected state points. The bcc-fcc phase transition is a weak first-order transition. The liquid-fcc–bcc triple point, which is determined by the interface-pinning method, has temperature 5.9 × 10−5 and pressure 2.5 × 10−6; the triple-point densities are 1.556 × 10−3 (liquid), 1.583 × 10−3 (bcc), and 1.587 × 10−3 (fcc).

AB - This paper determines the thermodynamic phase diagram of the EXP system of particles interacting by the purely repulsive exponential pair potential. The solid phase is face-centered cubic (fcc) at low densities and pressures. At higher densities and pressures, the solid phase is body-centered cubic (bcc) with a re-entrant liquid phase at the highest pressures simulated. The investigation first identifies the phase diagram at zero temperature at which the following four crystal structures are considered: fcc, bcc, hexagonal close packed, and cubic diamond. There is a T = 0 phase transition at pressure 2.651 × 10−3 with the thermodynamically stable structure being fcc below and bcc above this pressure. The densities of the two crystal structures at the phase transition are 1.7469 × 10−2 (fcc) and 1.7471 × 10−2 (bcc). At finite temperatures, the fcc–bcc, fcc-liquid, and bcc-liquid coexistence lines are determined by numerical integration of the Clausius–Clapeyron equation and validated by interface-pinning simulations at selected state points. The bcc-fcc phase transition is a weak first-order transition. The liquid-fcc–bcc triple point, which is determined by the interface-pinning method, has temperature 5.9 × 10−5 and pressure 2.5 × 10−6; the triple-point densities are 1.556 × 10−3 (liquid), 1.583 × 10−3 (bcc), and 1.587 × 10−3 (fcc).

UR - http://glass.ruc.dk/pdf/articles/2019_JChemPhys_150_174501.pdf

U2 - 10.1063/1.5094395

DO - 10.1063/1.5094395

M3 - Journal article

VL - 2019

JO - Journal of Chemical Physics

JF - Journal of Chemical Physics

SN - 0021-9606

IS - 150

M1 - 174501

ER -