Reaction coordinates for chemical reactions in solution are often of a collective nature involving solvent degrees of freedom. A recent generalization of the blue-moon ensemble technique has enabled us to determine the free energy required to change these variables, using them as constraints in a molecular dynamics simulation. We discuss a Ðrst application to the free energy of coordination Ñuc...

We establish a new and intriguing connection between the FokkerPlanck equation with gradient drift term and an associated free energy functional. Namely, we demonstrate that such a Fokker-Planck equation may be interpreted as a gradient flux, or a steepest descent, of a free energy functional with respect to a certain metric. This is accomplished through the construction of a time-discrete iter...

The one-loop free energy of the four-dimensional compact QED, which is known to be equivalent to the vector Sine-Gordon model, is calculated in the strong coupling regime. In the case, when the norm of the strength tensor of the saddle-point value of the corresponding Sine-Gordon model is much larger than the typical inverse area of a loop in the gas of the monopole rings, the obtained free ene...

The energetics of driven magnetic reconnections induced by the deformation of the magnetopause boundary due to the solar wind-magnetosphere interaction are studied. The bursty type reconnection ensues due to the forcing of the magnetopause boundary by the solar wind. For typical plasma parameters in the inner central plasma sheet (ICPS), the magnetic energy release during the reconnection is es...

The Ising model in two dimensions with the special boundary conditions of Brascamp and Kunz (BK) is analyzed. We derive exact finite-size corrections for the free energy F of the critical ferromagnetic Ising model on the M ×N square lattice with Brascamp–Kunz boundary conditions [H.J. Brascamp, H. Kunz, J. Math. Phys. 15 (1974) 66]. We show that finite-size corrections strongly depend not only ...

The Casimir free energy for a system of two dielectric concentric nonmagnetic spherical bodies is calculated with use of a quantum statistical mechanical method, at arbitrary temperature. By means of this rather novel method, which turns out to be quite powerful (we have shown this to be true in other situations also), we consider first an explicit evaluation of the free energy for the static c...

This paper is concerned with the geometrical shape, wetting length, and contact angle of a microdroplet on a fiber by using the method free energy variation. The governing equation and relevant boundary conditions of the microdroplet were re-derived based on the free energy variation of the droplet/fiber system. The geometrical shape of the droplet was determined as the combination of Legendre’...

We study the free energy of the Parabolic Anderson Model, a time-continuous model of directed polymers in random environment. We prove that in dimension 1 and 2, the free energy is always negative, meaning that very strong disorder always holds. The result for discrete polymers in dimension two, as well as better bounds on the free energy on dimension 1, were first obtained by Hubert Lacoin in ...

We present a parameterized analytical model of alchemical molecular binding. The model describes accurately the free energy profiles of linear single-decoupling alchemical binding free energy calculations. The parameters of the model, which are physically motivated, are obtained by fitting model predictions to numerical simulations. The validity of the model has been assessed on a set of host-g...

We introduce a new number–theoretic spin chain and explore its thermodynamics and connections with number theory. The energy of each spin configuration is defined in a translation–invariant manner in terms of the Farey fractions, and is also expressed using Pauli matrices. We prove that the free energy exists and exhibits a unique phase transition at inverse temperature β = 2. The free energy i...