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There are quantum statistical contributions to the free energy of formation of embryos and critical nuclei in transformations to condensed phases. They arise from consideration of the absolute entropy of the embryos or nuclei. In the case of homogeneous nucleation of water droplets from vapor the factor of increase in equilibrium concentration of critical nuclei is about 1017, resulting in a discrepancy of corresponding magnitude between the Becker-Doering equation and the critical supersaturation measurements of Wilson and Powell. It is suggested that some of this disagreement may be removed by treating the problem as a transient rather than a steady-state situation and considering non-accommodation in the smaller size classes. Also there is an appreciable quantum statistical effect in homogeneous nucleation of crystals from the supercooled liquid and a related effect in nucleation from the vapor of crystals on substrates.

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A simple method is developed to calculate Mie (Lennard‐Jones) potential parameters for metals, using crystalline state physical properties at any given temperature. Calculated values are in good agreement with some values reported in the literature.

Articles you may be interested inStudies on the structure, stability, and spectral signatures of hydride ion-water clusters J. Chem. Phys. 135, 214308 (2011); 10.1063/1.3663708Ion-water clusters, bulk medium effects, and ion hydration J. Chem. Phys. 135, 054505 (2011); 10.1063/1.3620077 Efficient ab initio path integral hybrid Monte Carlo based on the fourth-order Trotter expansion: Application to fluoride ion-water clusterThe properties of ion-water clusters. I. The protonated 21-water clusterThe procedures developed in this paper have been employed to calculate theoretical free energies of formation of ion-water clusters for comparison with experiment. Gibbs free energies were calculated for the gas phase reaction, ion(H 2 0)N_l +H 2 0(vapo,) = ion(H20)N' for the Li+, Na+, K+, Cl-, and F-ions and for N = 1-6. The standard state for all calculations was taken as 29S'K and 1 atm. The Monte Carlo method was used to evaluate the appropriate classical expressions of statistical mechanics by employing the intermolecular potential functions recently developed from ab initio Hartree--Fock calculations. Enthalpies, entropies, and structural information were also calculated. ~greement with experiment is sufficiently good to demonstrate the feasibility of this approach.