Stress-stress fluctuation formula for elastic constants in the NPT ensemble

Abstract

Several fluctuation formulas are available for calculating elastic constants from equilibrium correlation functions in computer simulations, but the ones available for simulations at constant pressure exhibit slow convergence properties and cannot be used for the determination of local elastic constants. To overcome these drawbacks, we derive a stress-stress fluctuation formula in the $NPT$ ensemble based on known expressions in the $NVT$ ensemble. We validate the formula in the $NPT$ ensemble by calculating elastic constants for the simple nearest-neighbor Lennard-Jones crystal and by comparing the results with those obtained in the $NVT$ ensemble. For both local and bulk elastic constants we find an excellent agreement between the simulated data in the two ensembles. To demonstrate the usefulness of the new formula, we apply it to determine the elastic constants of a simulated lipid bilayer.

arXiv comment10 pages, 4 figures

References in corpus (13)

• Local elasticity map and plasticity in a model Lennard-Jones glass
• Measuring Spatial Distribution of Local Elastic Modulus in Glasses
• Membrane-Protein Interactions in a Generic Coarse-Grained Model for Lipid Bilayers
• Structure of symmetric and asymmetric "ripple" phases in lipid bilayers
• Shear modulus of simulated glass-forming model systems: Effects of boundary condition, temperature and sampling time
• A Simple Computer Model for Liquid Lipid Bilayers
• Non-affine displacements in crystalline solids in the harmonic limit
• Coarse-Grained Simulations of Membranes under Tension
• Influence of Point Defects on the Shear Elastic Coefficients and on the Melting Temperature of Copper
• Shear stress relaxation and ensemble transformation of shear stress autocorrelation functions revisited
• Local Elastic Constants in Thin Films of an FCC Crystal
• Impulsive correction to the elastic moduli obtained using the stress-fluctuation formalism in systems with truncated pair potential
• Compressibility and pressure correlations in isotropic solids and fluids

Cited by in corpus (2)

• Calculation of elastic constants of embedded-atom-model potentials in the NVT ensamble
• Spatial distribution of local elastic moduli in nanocrystalline metals