PMID- 33498016
OWN - NLM
STAT- PubMed-not-MEDLINE
LR  - 20210421
IS  - 1361-648X (Electronic)
IS  - 0953-8984 (Linking)
VI  - 33
IP  - 15
DP  - 2021 Feb 24
TI  - Investigating the energetic and entropic components of effective potentials 
      across a glass transition.
LID - 10.1088/1361-648X/abdff8 [doi]
AB  - By eliminating unnecessary details, coarse-grained (CG) models provide the 
      necessary efficiency for simulating scales that are inaccessible to higher 
      resolution models. However, because they average over atomic details, the 
      effective potentials governing CG degrees of freedom necessarily incorporate 
      significant entropic contributions, which limit their transferability and 
      complicate the treatment of thermodynamic properties. This work employs a 
      dual-potential approach to consider the energetic and entropic contributions to 
      effective interaction potentials for CG models. Specifically, we consider one- 
      and three-site CG models for ortho-terphenyl (OTP) both above and below its glass 
      transition. We employ the multiscale coarse-graining (MS-CG) variational 
      principle to determine interaction potentials that accurately reproduce the 
      structural properties of an all-atom (AA) model for OTP at each state point. We 
      employ an energy-matching variational principle to determine an energy operator 
      that accurately reproduces the intra- and inter-molecular energy of the AA model. 
      While the MS-CG pair potentials are almost purely repulsive, the corresponding 
      pair energy functions feature a pronounced minima that corresponds to contacting 
      benzene rings. These energetic functions then determine an estimate for the 
      entropic component of the MS-CG interaction potentials. These entropic functions 
      accurately predict the MS-CG pair potentials across a wide range of liquid state 
      points at constant density. Moreover, the entropic functions also predict pair 
      potentials that quite accurately model the AA pair structure below the glass 
      transition. Thus, the dual-potential approach appears a promising approach for 
      modeling AA energetics, as well as for predicting the temperature-dependence of 
      CG effective potentials.
CI  - Creative Commons Attribution license.
FAU - Szukalo, Ryan J
AU  - Szukalo RJ
AD  - Department of Chemistry, Penn State University, University Park, PA 16802 United 
      States of America.
FAU - Noid, W G
AU  - Noid WG
AUID- ORCID: 0000-0001-9675-8489
AD  - Department of Chemistry, Penn State University, University Park, PA 16802 United 
      States of America.
LA  - eng
PT  - Journal Article
DEP - 20210224
PL  - England
TA  - J Phys Condens Matter
JT  - Journal of physics. Condensed matter : an Institute of Physics journal
JID - 101165248
SB  - IM
OTO - NOTNLM
OT  - coarse-grained models
OT  - effective potentials
OT  - entropy
OT  - glass transition
OT  - liquids
OT  - multiscale modeling
OT  - statistical mechanics
EDAT- 2021/01/27 06:00
MHDA- 2021/01/27 06:01
CRDT- 2021/01/26 20:15
PHST- 2020/11/30 00:00 [received]
PHST- 2021/01/26 00:00 [accepted]
PHST- 2021/01/27 06:00 [pubmed]
PHST- 2021/01/27 06:01 [medline]
PHST- 2021/01/26 20:15 [entrez]
AID - 10.1088/1361-648X/abdff8 [doi]
PST - epublish
SO  - J Phys Condens Matter. 2021 Feb 24;33(15). doi: 10.1088/1361-648X/abdff8.