Constant pressure molecular

An algorithm for performing a constant-pressure molecular dynamics simulation that resolves some unphysical observations in the extended system (Andersen s) method and Berendsen s methods was developed by Feller et al. [29]. This approach replaces the deterministic equations of motion with the piston degree of freedom added to the Langevin equations of motion. This eliminates the unphysical fluctuation of the volume associated with the piston mass. In addition, Klein and coworkers [30] present an advanced constant-pressure method to overcome an unphysical dependence of the choice of lattice in generated trajectories. 

Tu, K. Klein, M. Tobias, D. J., Constant-pressure molecular dynamics investigations of cholesterol effects in a dipalmitoylphosphatidylchohne bilayer, Biophys. J. 1998, 75, 2147-2156. 

Chem. Solids, 56, 501 (1995). First-Principle-Constant Pressure Molecular Dynamics. 

W. G. Hoover, Molecular Dynamics, Springer-Verlag, New York, 1986 W. G. Hoover, Constant-Pressure Equations of Motion, Phys. Rev. A 34 (1986y) 2499-2500 D. J. Evans and G. P. Morriss, The Isothermal/Isobaric Molecular Dynamics Ensemble, Phys. Lett. 98A (1983) 433-436 G. J. Martyna, D. J. Tobias and M. L. Klein, Constant Pressure Molecular Dynamics Algorithms, J. Chem. Phys. 101 (1994) 4177-4189. 

S. Nose and M. L. Klein, Mol. Phys., 50, 1055 (1983). Constant Pressure Molecular Dynamics for Molecular Systems. 

Nose, S. and Klein, M. L. (1983) Constant pressure molecular dynamics for molecular systems, Mol. Phys. A, 1055-1076. 

M. Bernasconi, G. L. Chiarotti, R Focher, S. Scandolo, E. Tosatti, and M. Parrinello (1995) First-principle-constant pressure molecular dynamics. J. Phys. Chem. Solids 56, p. 501... 

Feller, S., Zhang, Y., Pastor, R., Brooks, B. Constant pressure molecular dynamics simulation The Langevin piston method. J. Chem. Phys. 1995,103, 4613-21. 

Martyna, G.J., Tobias, D.J., Klein, M.L. Constant pressure molecular dynamics algorithms. J. Chem. Phys. 1994,101, 4177-89. 

Ti-wadeite, but structural similarity in the case of Zr-wadeite. These differences/ similarities influence the energetics of nucleation, with the result that it is more difficult to form a critical nucleus of Ti-wadeite. Vessal and Dickinson (1994) have undertaken both constant volume and constant pressure molecular dynamics simulations to test this hypothesis. 

In principle, the modeller has the choice of using either the Monte Carlo or molecular d)mamics technique for a given simulation. In practice one technique must be chosen over the other. Sometimes the decision is a trivial one, for example because a suitable program is readily available. In other cases there are clear reasons for choosing one method instead of the other. For example, molecular dynamics is required if one wishes to calculate time-dependent quantities such as transport coefficients. Conversely, Monte Carlo is often the most appropriate method to investigate systems in certain ensembles for example, it is much easier to perform simulations at exact temperatures and pressures with the Monte Carlo method than using the sometimes awkward and ill-defined constant temperature and constant pressure molecular d)mamics simulation methods. The Monte Carlo method is also well suited to certain types of models such as the lattice models. 

Wang, J., and M. S. Gutierrez. 2010. Molecular structural transformation of 2 1 clay minerals by a constant-pressure molecular dynamics simulation method. Journal of Nanomaterials 2010 1-13. doi 10.1155/2010/795174. 

For many problems, however, it is more convenient to keep the temperature, pressure, or chemical potential constant, instead of the total energy, volume, and number of particles. Generalizations of the molecular dynamics technique to virtually any ensemble have been developed, and they will be discussed in the following chapters. Of course, constant temperature MD does not conserve the total system energy, allowing it to fluctuate as is required at constant temperature. Similarly, volume is allowed to fluctuate in constant pressure molecular dynamics. The trick is to make these quantities fluctuate in a manner consistent with the probability distribution of the desired ensemble. 

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