APBS is a software package for the numerical solution of the
Poisson-Boltzmann equation (PBE), one of the most popular continuum
models for describing electrostatic interactions between molecular
solutes in salty, aqueous media. APBS was designed to efficiently
evaluate electrostatic properties for such simulations for a wide
range of length scales to enable the investigation of molecules with
tens to millions of atoms. It is also widely used in molecular
visualization (in such applications as PyMOL).
