scholarly journals Structure and Dynamics of Zr4+ in Aqueous Solution: An Ab Initio QM/MM Molecular Dynamics Study

2015 ◽  
Vol 15 (2) ◽  
pp. 155-162 ◽  
Author(s):  
Suwardi Suwardi ◽  
Harno Dwi Pranowo ◽  
Ria Armunanto
Keyword(s):  
Molecular Dynamics ◽  
Aqueous Solution ◽  
Distribution Function ◽  
Pair Potential ◽  
Structural Data ◽  
Angular Distribution Function ◽  
Dilute Aqueous Solution ◽  
Dynamical Properties ◽  
Experimental Values ◽  
Three Body

A QM/MM molecular dynamics (MD) simulation has been carried out using three-body corrected pair potential to investigate the structural and dynamical properties of Zr4+ in dilute aqueous solution. Structural data in the form of radial distribution function, coordination number distribution, and angular distribution function were obtained. The results indicate eight water molecules coordinate to zirconium ion and have two angles of O-Zr4+-O, i.e. 72.0° and 140.0° with a Zr4+-O distance of 2.34 Å. According to these results, the hydration structure of Zr4+ ion in water was more or less well-defined square antiprismatic geometry. The dynamical properties have been characterized by the ligand’s mean residence time (MRT) and Zr4+-O stretching frequencies. The inclusion of the three-body correction was important for the description of the hydrated Zr4+ ion, and the results indicated in good agreement with experimental values.

scholarly journals Molecular Dynamics Calculation of the Thermodynamic Properties of Methane

1975 ◽  
Vol 28 (3) ◽  
pp. 315 ◽  
Author(s):  
HJM Hanley ◽  
RO Watts
Keyword(s):  
Molecular Dynamics ◽  
Thermodynamic Properties ◽  
Specific Heat ◽  
Low Temperatures ◽  
Spherically Symmetric ◽  
Method Of Molecular Dynamics ◽  
Experimental Values ◽  
Dynamics Calculation ◽  
Liquid States ◽  
Three Body

Thermodynamic properties of methane in the dense gas and liquid states have been calculated by the method of molecular dynamics. The methane pair interactions were modelled using a spherically symmetric m-6-8 potential, and the most significant three-body and quantum effects were included. Agreement between calculated and experimental values for the energy and pressure is generally good except at low temperatures and high densities. The specific heat at constant volume is also briefly discussed.

A Molecular Dynamics Simulation of the Transport Properties of Molten (La1/3, K)Cl

2005 ◽  
Vol 60 (3) ◽  
pp. 187-192 ◽  
Author(s):  
Masahiko Matsumiya ◽  
Koichi Seo
Keyword(s):  
Molecular Dynamics ◽  
Charge Asymmetry ◽  
The Self ◽  
Dynamics Simulation ◽  
Alkali Chloride ◽  
Self Diffusion ◽  
Dynamical Properties ◽  
Experimental Values ◽  
Dynamics Simulations ◽  
Self Diffusion Coefficient

Molecular dynamics simulations of molten (La1/3, K)Cl at 1123 K have been performed in order to investigate the correlation between simulated dynamical properties such as the self-exchange velocity (ν), the self-diffusion coefficient (D) and the electrical conductivity (κ) and the corresponding experimental values. The simulated results revealed that v and D of potassium decrease with increasing mole fraction of lanthanum, as expected from the experimental internal cation mobilities, b. The decrease of bK, νK and DK is ascribed to the tranquilization effect by La3+, which strongly interacts with Cl−. In contrast, bLa, νLa, and DLa increase with increasing concentration of La3+. The distorted linkage of the network structure of [LaCl6]3− units was disconnected with increasing the concentration of the alkali chloride. This might be attributed to the stronger association of La3+ with Cl− due to the enhanced charge asymmetry of the two cations neighboring Cl−. The sequence of the calculated v’s, D’s, and κ’s is consistent with those of the referred experimental results.

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