Molecular Dynamics Simulation of Tri-n-Butyl-Phophate Liquid: A Force Field Comparative Study

Journal Article · Sun Jan 01 04:00:00 EST 2012 · Journal of Physical Chemistry B

DOI:https://doi.org/10.1021/jp207089e· OSTI ID:1033528

Cui, Shengting ^[1]; de Almeida, Valmor F ^[1]; Hay, Benjamin ^[1]; Ye, Xianggui ^[1]; Khomami, Bamin ^[1]

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1. ORNL

Molecular dynamics (MD) simulations were conducted to compare the performance of four force fields in predicting thermophysical properties of tri-n-butyl-phosphate (TBP) in the liquid phase. The intramolecular force parameters used were from the Assisted Model Building with Energy Refinement (AMBER) force field model. The van der Waals parameters were based on either the AMBER or the Optimized Potential for Liquid Simulation (OPLS) force fields. The atomic partial charges were either assigned by performing quantum chemistry calculations or utilized previously published data, and were scaled to approximate the average experimental value of the electric dipole moment. Canonical ensemble computations based on the aforementioned parameters were performed near the atmospheric pressure and temperature to obtain the electric dipole moment, mass density, and self-diffusion coefficient. In addition, the microscopic structure of the liquid was characterized via pair correlation functions between selected atoms. It has been demonstrated that the electric dipole moment can be approximated within 1% of the average experimental value by virtue of scaled atomic partial charges. The liquid mass density can be predicted within 0.5-1% of its experimentally determined value when using the corresponding charge scaling. However, in all cases the predicted self- diffusion coefficient is significantly smaller than a commonly quoted experimental measurement; this result is qualified by the fact that the uncertainty of the experimental value was not available.

• Research Organization: Oak Ridge National Laboratory (ORNL)
• Sponsoring Organization: ME USDOE - Office of Management, Budget, and Evaluation; ORNL work for others
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 1033528
• Journal Information: Journal of Physical Chemistry B, Journal Name: Journal of Physical Chemistry B Journal Issue: 1 Vol. 116; ISSN 1520-6106
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
ATMOSPHERIC PRESSURE
ATOMS
COMPARATIVE EVALUATIONS
CORRELATION FUNCTIONS
DIFFUSION
ELECTRIC DIPOLE MOMENTS
MOLECULAR DYNAMICS METHOD
PERFORMANCE
PHYSICAL PROPERTIES
SELF-DIFFUSION
SIMULATION
TBP
THERMODYNAMIC PROPERTIES