Molecular Dynamics implementation of BN2D or Mercedes Benz water model ?
Two-dimensional Mercedes Benz (MB) or BN2D water model (Naim, 1971) is implemented in Molecular Dynamics. It is known that the MB model can capture abnormal properties of real water (high heat capacity, minima of pressure and isothermal compressibility, negative thermal expansion coefficient) (Silverstein etal., 1998). In this work formulas for calculating the thermodynamic, structural and dynamic properties in microcanonical (NVE) and isothermalisobaric (NPT) ensembles for the model from Molecular Dynamics simulation are derived and verified against known Monte Carlo results. The convergence of the thermodynamic properties and the systems numerical stability are investigated. The results qualitatively reproduce the peculiarities of real water making the model a visually convenient tool that also requires less computational resources, thus allowing simulations of large (hydrodynamic scale) molecular systems. We provide the open source code written in C/C++ for the BN2D water model implementation using Molecular Dynamics. Program title: BN2DMD Catalogue identifier: AEVJ_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEVJ_v1_0.html Program obtainable from: CPC Program Library, Queens University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 3120 No. of bytes in distributed program, including test data, etc.: 274895 Distribution format: tar.gz Programming language: C/C++. Computer: Workstation. Operating system: Linux, Unix. Classification: 16.9. Nature of problem: Molecular dynamics simulation of BN2D or Mercedes Benz water model. Solution method: A BN2D water model [2], microcanonical (NVE) and isothermalisobaric (NPT) ensembles with velocity-Verlet and PredictorCorrector integration [1] respectively. Rotational degree of freedom is treated differently in NVE and NPT ensembles due to the nature of the model. Restrictions: Memory and CPU time limits the size of simulations. Running time: Depends on the size of system. References: A. B. Naim, Statistical mechanics of waterlike particles in two dimensions. i. physical model and application of the PercusYevick equation, J. Chem. Phys. vol. 54, p. 3682, 1971. K. A. T. Silverstein, A. D. J. Haymet, and K. A. Dill, A simple model of water and the hydrophobic effect, J. Am. Chem. Soc. vol. 120, pp. 31663175, 1998.
molecular dynamics bn2d nve npt thermodynamic properties 2d mercedes benz model radial distribution function autocorrelation functions