@article{herce_perera_darden_sagui_2005, title={Surface solvation for an ion in a water cluster}, volume={122}, ISSN={["0021-9606"]}, DOI={10.1063/1.1829635}, abstractNote={We have used molecular dynamics simulations to study the structural, dynamical, and thermodynamical properties of ions in water clusters. Careful evaluations of the free energy, internal energy, and entropy are used to address controversial or unresolved issues, related to the underlying physical cause of surface solvation, and the basic assumptions that go with it. Our main conclusions are the following. (i) The main cause of surface solvation of a single ion in a water cluster is both water and ion polarization, coupled to the charge and size of the ion. Interestingly, the total energy of the ion increases near the cluster surface, while the total energy of water decreases. Also, our analysis clearly shows that the cause of surface solvation is not the size of the total water dipole (unless this is too small). (ii) The entropic contribution is the same order of magnitude as the energetic contribution, and therefore cannot be neglected for quantitative results. (iii) A pure energetic analysis can give a qualitative description of the ion position at room temperature. (iv) We have observed surface solvation of a large positive iodinelike ion in a polarizable water cluster, but not in a nonpolarizable water cluster.}, number={2}, journal={JOURNAL OF CHEMICAL PHYSICS}, author={Herce, DH and Perera, L and Darden, TA and Sagui, C}, year={2005}, month={Jan} }
 @article{herce_darden_sagui_2003, title={Calculation of ionic charging free energies in simulation systems with atomic charges, dipoles, and quadrupoles}, volume={119}, DOI={10.1063/1.1609191}, abstractNote={The ionic charging free energy is a very sensitive probe for the treatment of electrostatics in any given simulation setting. In this work, we present methods to compute the ionic charging free energy in systems characterized by atomic charges and higher-order multipoles, mainly dipoles and quadrupoles. The results of these methods for periodic boundary conditions and for spherical clusters are then compared. For the treatment of spherical clusters, we introduce a generalization of Gauss’ law that links the microscopic variables to the measurable macroscopic electrostatics via a work function.}, number={15}, journal={Journal of Chemical Physics}, author={Herce, H. D. and Darden, T. and Sagui, C.}, year={2003}, pages={7621–7632} }
 @article{herce_zemba_2002, title={A new class of matrix models arising from the W1+infinity algebra}, volume={537}, ISSN={["1873-2445"]}, DOI={10.1016/S0370-2693(02)01879-8}, abstractNote={We present a new class of Hermitian one-matrix models originated in the W1+∞ algebra: more precisely, the polynomials defining the W1+∞ generators in their fermionic bilinear form are shown to expand the orthogonal basis of a class of random Hermitian matrix models. The corresponding potentials are given, and the thermodynamic limit interpreted in terms of a simple plasma picture. The new matrix models can be successfully applied to the full bosonization of interesting one-dimensional systems, including all the perturbative orders in the inverse size of the system. As a simple application, we present the all-order bosonization of the free fermionic field on the one-dimensional lattice.}, number={1-2}, journal={PHYSICS LETTERS B}, author={Herce, HD and Zemba, GR}, year={2002}, month={Jun}, pages={141–146} }