Simultaneously, the major families of biomolecular force fields have undergone multiple rounds of development and improvement. For any force field, this reparametrization process requires significant time and resource investment to identify errors, develop corrections, and validate the accuracy of the new parameters. The functional form of each force field, which provides the framework for parameter optimization, has therefore remained relatively unchanged and similar between families for decades. With small variations between force field families, each typically features a simple harmonic representation of bonds and angles, a Fourier series for proper dihedrals, a Lennard-Jones model of van der Waals (vdW) interactions, and most importantly, an additive, fixed-point-charge representation of electrostatic interactions. The philosophy for parametrization of these fixed-point-charges varies between families and has seen substantial modification between force field iterations, but generally entails a significant focus on fitting to either molecular electrostatic potentials (for example of sidechain fragments), interaction energies, or derived thermodynamic properties. For a given biomolecule, these electrostatic and vdW parameters are then relied upon to accurately recreate interatomic interactions in all possible environments.