The Advances in Chemical Physics series provides the chemical physics field with a forum for critical, authoritative evaluations of advances in every area of the discipline. This volume explores the following topics: Thermodynamic Perturbation Theory for Associating MoleculesPath Integrals and Effective Potentials in the Study of Monatomic Fluids at EquilibriumSponteneous Symmetry Breaking in Matter Induced by Degeneracies and PseudogeneraciesMean-Field Electrostatics Beyond the Point-Charge DescriptionFirst Passage Processes in Cellular BiologyTheoretical Modeling of Vibrational Spectra and Proton Tunneling in Hydroen-Bonded Systems