PMID- 21806095
OWN - NLM
STAT- MEDLINE
DCOM- 20111115
LR  - 20121115
IS  - 1089-7690 (Electronic)
IS  - 0021-9606 (Linking)
VI  - 135
IP  - 4
DP  - 2011 Jul 28
TI  - Particle-based multiscale coarse graining with density-dependent potentials: 
      application to molecular crystals (hexahydro-1,3,5-trinitro-s-triazine).
PG  - 044112
LID - 10.1063/1.3607603 [doi]
AB  - We describe the development of isotropic particle-based coarse-grain models for 
      crystalline hexahydro-1,3,5-trinitro-s-triazine (RDX). The coarse graining 
      employs the recently proposed multiscale coarse-graining (MS-CG) method, which is 
      a particle-based force-matching approach for deriving free-energy effective 
      interaction potentials. Though one-site and four-site coarse-grain (CG) models 
      were parameterized from atomistic simulations of non-ordered (molten and ambient 
      temperature amorphous) systems, the focus of the paper is a detailed study of the 
      one-site model with a brief recourse to the four-site model. To improve the 
      ability of the one-site model to be applied to crystalline phases at various 
      pressures, it was found necessary to include explicit dependence on a particle 
      density, and a new theory of local density-dependent MS-CG potentials is 
      subsequently presented. The density-dependency is implemented through 
      interpolation of MS-CG force fields derived at a preselected set of reference 
      densities. The computationally economical procedure for obtaining the reference 
      force fields starting from the interaction at ambient density is also described. 
      The one-site MS-CG model adequately describes the atomistic lattice structure of 
      alpha-RDX at ambient and high pressures, elastic and vibrational properties, 
      pressure-volume curve up to P = 10 GPa, and the melting temperature. In the 
      molten state, the model reproduces the correct pair structure at different 
      pressures as well as higher order correlations. The potential of the MS-CG model 
      is further evaluated in simulations of shocked crystalline RDX.
CI  - (c) 2011 American Institute of Physics
FAU - Izvekov, Sergei
AU  - Izvekov S
AD  - U.S. Army Research Laboratory, Aberdeen Proving Ground, Maryland 21005, USA. 
      sergiy.izvyekov@us.army.mil
FAU - Chung, Peter W
AU  - Chung PW
FAU - Rice, Betsy M
AU  - Rice BM
LA  - eng
PT  - Journal Article
PT  - Research Support, U.S. Gov't, Non-P.H.S.
PL  - United States
TA  - J Chem Phys
JT  - The Journal of chemical physics
JID - 0375360
RN  - 0 (Explosive Agents)
RN  - 0 (Triazines)
RN  - W91SSV5831 (cyclonite)
SB  - IM
MH  - Computer Simulation
MH  - Crystallization
MH  - Elasticity
MH  - Explosive Agents/*chemistry
MH  - Freezing
MH  - Models, Molecular
MH  - Temperature
MH  - Triazines/*chemistry
EDAT- 2011/08/03 06:00
MHDA- 2011/11/16 06:00
CRDT- 2011/08/03 06:00
PHST- 2011/08/03 06:00 [entrez]
PHST- 2011/08/03 06:00 [pubmed]
PHST- 2011/11/16 06:00 [medline]
AID - 10.1063/1.3607603 [doi]
PST - ppublish
SO  - J Chem Phys. 2011 Jul 28;135(4):044112. doi: 10.1063/1.3607603.