KBKit: A Python Toolkit for Kirkwood–Buff Theory from Molecular Dynamics

2020, 10, 771) extrapolation to the thermodynamic limit. Built-in convergence diagnostics alert users when Kirkwood-Buff integrals (KBIs) fail to meet established quality criteria. Using input from standard GROMACS output files, KBKit automatically computes KBIs and derived thermodynamic quantities, including: activity coefficients, excess Gibbs energy, and zero-wavevector structure factors, for both multicomponent and electrolyte systems. Written with modern software-engineering practices such as continuous integration, extensive unit testing, and thorough documentation, KBKit is both reliable and easy to extend. By condensing the complex KBI correction and analysis workflow into a few intuitive commands, KBKit enables researchers to incorporate KB theory into routine simulation workflows and accelerate the characterization of solution-phase thermodynamics.