A new approach, consisting of using radial basis function networks to obtain the long-range part of diatomic potential energy functions from simulated second virial coefficients, is presented. From these simulated data the artiÐcial neural network was able not only to learn but also to predict properties for systems that were not considered during the training process. Fifteen di†erent diatomic...

Bacteria typically have a few thousand different proteins. The number of proteins with a given charge is a roughly Gaussian function of charge — centred near zero, and with a width around ten (in units of the charge on the proton). We have used the charges on E. coli’s proteins to estimate the changes in the second virial coefficients of all its proteins as the concentration of a 1:1 salt is in...

The authors construct a rigid-body (five-dimensional) potential energy surface for the water-nitrogen complex using the systematic intermolecular potential extrapolation routine. The intermolecular potential is then extrapolated to the limit of a complete basis set. An analytic fit of this surface is obtained, and, using this, the global minimum energy is found. The minimum is located in an arr...

We present Mayer-sampling Monte Carlo calculations of the quantum Boltzmann contribution to the virial coefficients B(n), as defined by path integrals, for n = 2 to 4 and for temperatures from 2.6 K to 1000 K, using state-of-the-art ab initio potentials for interactions within pairs and triplets of helium-4 atoms. Effects of exchange are not included. The vapor-liquid critical temperature of th...

It was recently shown that vapor-liquid coexistence densities derived from Mie and Yukawa models collapse to define a single master curve when represented against the difference between the reduced second virial coefficient at the corresponding temperature and that at the critical point. In this work, we further test this proposal for another generalization of the Lennard-Jones pair potential. ...

We derive an analytical expression of the second virial coefficient of d-dimensional hard sphere fluids confined to slit pores by applying Speedy and Reiss' interpretation of cavity space. We confirm that this coefficient is identical to the one obtained from the Mayer cluster expansion up to second order with respect to fugacity. The key step of both approaches is to evaluate either the surfac...

Measurements of liquid-liquid phase transition temperatures (cloud points) of mixtures of a protein (lysozyme) and a polymer, poly(ethylene glycol) (PEG) show that the addition of low molecular weight PEG stabilizes the mixture whereas high molecular weight PEG was destabilizing. We demonstrate that this behavior is inconsistent with an entropic lysozyme-PEG depletion interaction and suggest th...

Inside living cells are complex mixtures of thousands of components. It is hopeless to try to characterize all the individual interactions in these mixtures. Thus, we develop a statistical approach to approximating them, and examine the conditions under which the mixtures phase separate. The approach approximates the matrix of second-virial coefficients of the mixture by a random matrix, and de...