Obtaining accurate pressure second virial coefficients for methane from an ab initio pair potential

1991 ◽  
Vol 95 (12) ◽  
pp. 9106-9114 ◽  
Author(s):  
David H. Gay ◽  
Houfeng Dai ◽  
Donald R. Beck
Keyword(s):  
Ab Initio ◽  
Pair Potential ◽  
Virial Coefficients ◽  
Second Virial Coefficients

Calculation of Thermodynamical, Transport and Structural Properties of Neon in Liquid and Supercritical Phases by Molecular Dynamics Simulations Using an Accurate ab initio Pair Potential

2003 ◽  
Vol 68 (3) ◽  
pp. 627-643 ◽  
Author(s):  
Muthusamy Venkatraj ◽  
Markus G. Müller ◽  
Hanspeter Huber ◽  
Robert J. Gdanitz
Keyword(s):  
Molecular Dynamics ◽  
Ab Initio ◽  
Structural Properties ◽  
Pair Potential ◽  
Virial Coefficients ◽  
Energy Curve ◽  
Second Virial Coefficients ◽  
Analytical Potential ◽  
Supercritical Phase ◽  
Dynamics Simulations

An analytical potential energy curve (NE3) is constructed from points obtained by accurate ab initio calculations. The quality of the pair potential is established by a comparison of calculated and experimental second virial coefficients as a function of temperature. Molecular dynamics equilibrium simulations are performed with the NE3 potential for pressures between 20 and 1000 MPa and temperatures between 100 and 600 K in the supercritical phase and for one point in the liquid phase of neon. The properties are compared with those obtained from experiment. It is found that the accurate pair potential has a large effect on pressure, energies and enthalpies and a significant influence on other thermodynamic properties but little influence on transport and structural properties. In the supercritical phase the deviation between the calculated quantum-corrected and experimental pressure values is always less than 2%.

MODELING THERMOPHYSICAL PROPERTIES OF NOBLE GAS INVOLVED MIXTURES

2011 ◽  
Vol 08 (01) ◽  
pp. 19-39 ◽  
Author(s):  
MOHAMMAD MEHDI PAPARI ◽  
JALIL MOGHADASI ◽  
SOUDABEH NIKMANESH ◽  
ELHAM HOSSEINI ◽  
ALI BOUSHEHRI
Keyword(s):  
Thermal Conductivity ◽  
Potential Energy ◽  
Thermophysical Properties ◽  
Noble Gas ◽  
Pair Potential ◽  
Virial Coefficients ◽  
Model Potential ◽  
Intermolecular Potential ◽  
Inversion Method ◽  
Second Virial Coefficients

The present work involves in determining isotropic and effective pair potential energy of binary gas mixtures of Kr–Xe , Kr–C2H6 , Xe–C2H6 , Kr–C3H8 , and Xe–C3H8 from thermophysical properties consisting of viscosity and second virial coefficients through inversion method. Typically, the calculated intermolecular potential energy of Kr–Xe system has compared with HFD model potential reported in literature. A desirable harmony between our model potential and HFD model has been obtained. In order to assess the potential energies obtained, transport properties including viscosity, diffusion, thermal diffusion factor, and thermal conductivity of aforementioned mixtures were predicted using the calculated models potential. The deviation percentage of the calculated viscosity and thermal conductivity of above-mentioned mixtures from the literature values are, respectively, within ±2%, ±3%.

Second Virial Coefficients of Ground State Nitrogen Atoms

1976 ◽  
Vol 31 (12) ◽  
pp. 1722-1724 ◽  
Author(s):  
C. Guidotti ◽  
G. P. Arrighini ◽  
M. Capitelli ◽  
U. T. Lamanna
Keyword(s):  
Ab Initio ◽  
Ground State ◽  
Virial Coefficients ◽  
Nitrogen Molecule ◽  
Repulsive Potential ◽  
Second Virial Coefficients ◽  
Temperature Range

Abstract Second virial coefficients of ground state nitrogen atoms have been calculated in the temperature range 6000 - 20000 K. The results have been obtained using experimental potentials for the states 1∑g+, 3∑u+5∑g+ and of the nitrogen molecule and an ab initio Heitler-London potential for the 2∑u+ repulsive potential. Differences up to a factor of 5 are found between the present second virial coefficients and the corresponding values of Kessel'man et al.

The Second Virial Coefficients of n-Alkanes and Their Mixtures from the Kihara Convex Core Intermolecular Pair Potential

1993 ◽  
Vol 58 (10) ◽  
pp. 2489-2504 ◽  
Author(s):  
Jan Pavlíček ◽  
Karel Aim ◽  
Tomáš Boublík
Keyword(s):  
Geometric Mean ◽  
Second Virial Coefficient ◽  
Pair Potential ◽  
Virial Coefficients ◽  
Liquid Density ◽  
Second Virial Coefficients ◽  
Uncertainty Estimates ◽  
Pure Compounds ◽  
The Individual ◽  
Convex Core

The second virial coefficients for a series of C2 to C8 n-alkanes and the second virial cross coefficients for their binary mixtures were calculated as a function of temperature from the exact expressions derived for the Kihara rod-like molecules. The three parameters of Kihara pair potential, ε/k, σ and l for the individual compounds were either used as determined from vapour-liquid equilibrium and saturated liquid density data in a previous study or with ε/k adjusted to the second virial coefficient data. The results are accurate almost within experimental uncertainty estimates of the data. In the case of mixtures the second virial cross coefficients were calculated from a similar expression in which only the ε12/k parameter was adjusted whereas σ12 = (σ1 + σ2)/2 and l1 and l2 of pure compounds were employed. It appears that the correction factor to the geometric mean combining rule for ε12/k is always less than and close to unity. Comparison with the values obtained from the Tsonopoulos generalized correlation reveals fair agreement between the characteristic binary k12 parameters from the two methods.

Ab initio calculation of the refractivity and hyperpolarizability second virial coefficients of neon gas

2003 ◽  
Vol 101 (13) ◽  
pp. 1983-1995 ◽  
Author(s):  
CHRISTOF HATTIG ◽  
JAVIER CACHEIRO ◽  
BERTA FERNANDEZ ◽  
ANTONIO RIZZO
Keyword(s):  
Ab Initio ◽  
Ab Initio Calculation ◽  
Virial Coefficients ◽  
Second Virial Coefficients ◽  
Neon Gas
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