Potential Energy Landscape Equation of State

Potential energy landscape equation of state.

Depth, number, and shape of the basins of the potential energy landscape are the key ingredients of the inherent structure thermodynamic formalism introduced by Stillinger and Weber [F. H. Stillinger and T. A. Weber, Phys. Rev. A 25, 978 (1982)]. Within this formalism, an equation of state based only on the volume dependence of these landscape properties is derived. Vibrational and configuratio...

The Equation of State of an Energy Landscape

Certifying the Potential Energy Landscape

It is highly desirable for numerical approximations to stationary points for a potential energy landscape to lie in the corresponding quadratic convergence basin. However, it is possible that an approximation may lie only in the linear convergence basin, or even in a chaotic region, and hence not converge to the actual stationary point when further optimization is attempted. Proving that a nume...

Equation of State of the Energy Landscape of SPC/E Water

The contributions to the thermodynamics of liquid SPC/E water from its inherent structures have been determined over a broad range of temperature and density (220-500 K, 0.8-1.25 g/cm3). Molecular dynamics simulations of shifted-force SPC/E water give a retracing locus of density maxima in the equilibrium liquid with a retracing point at ca. 275 K and -200 bar, showing that over a large range o...

Certification and the potential energy landscape.

Typically, there is no guarantee that a numerical approximation obtained using standard nonlinear equation solvers is indeed an actual solution, meaning that it lies in the quadratic convergence basin. Instead, it may lie only in the linear convergence basin, or even in a chaotic region, and hence not converge to the corresponding stationary point when further optimization is attempted. In some...