title: A generalized Poisson and Poisson-Boltzmann solver for electrostatic environments.
abstract: The computational study of chemical reactions in complex, wet environments is critical for applications in many fields. It is often essential to study chemical reactions in the presence of applied electrochemical potentials, taking into account the non-trivial electrostatic screening coming from the solvent and the electrolytes. As a consequence, the electrostatic potential has to be found by solving the generalized Poisson and the Poisson-Boltzmann equations for neutral and ionic solutions, respectively. In the present work, solvers for both problems have been developed. A preconditioned conjugate gradient method has been implemented for the solution of the generalized Poisson equation and the linear regime of the Poisson-Boltzmann, allowing to solve iteratively the minimization problem with some ten iterations of the ordinary Poisson equation solver. In addition, a self-consistent procedure enables us to solve the non-linear Poisson-Boltzmann problem. Both solvers exhibit very high accuracy and parallel efficiency and allow for the treatment of periodic, free, and slab boundary conditions. The solver has been integrated into the BigDFT and Quantum-ESPRESSO electronic-structure packages and will be released as an independent program, suitable for integration in other codes.
authors.affiliation: Department of Physics, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland.
authors.forename: G
authors.initials: G
authors.lastname: Fisicaro
authors.affiliation: University of Grenoble Alpes, CEA, INAC-SP2M, L_Sim, F-38000 Grenoble, France.
authors.forename: L
authors.initials: L
authors.lastname: Genovese
authors.affiliation: Institute of Computational Science, Università della Svizzera Italiana, Via Giuseppe Buffi 13, CH-6904 Lugano, Switzerland.
authors.forename: O
authors.initials: O
authors.lastname: Andreussi
authors.affiliation: Theory and Simulations of Materials (THEOS) and National Centre for Computational Design and Discovery of Novel Materials (MARVEL), École Polytechnique Fédérale de Lausanne, Station 12, CH-1015 Lausanne, Switzerland.
authors.forename: N
authors.initials: N
authors.lastname: Marzari
authors.affiliation: Department of Physics, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland.
authors.forename: S
authors.initials: S
authors.lastname: Goedecker