Properties reliant on a balance of intermolecular interactions and conformational propensities, such as solvation or binding free energies, exploration of structural and dynamical ensembles, or kinetics of transitions, are likely to be recreated successfully with well-parametrized additive models through compensatory effects of the remaining potential function terms. Both the Amber ff14SB and Charmm C36m force fields have been well validated for their ability to accurately recreate biomolecular structure and dynamics. AMOEBA, or other equally accurate polarizable models, may provide significant improvement in accuracy when the electric field is the crucial property of interest. Notably, our results suggest this is true even for electric fields encountered in 'normal' protein environments -the maximum electric field magnitudes encountered in CypA (approximately ±75 MV cm -1 from Fig. ) are well below those measured in more 'extreme' environments, such as the active site of ketosteroid isomerase. Beyond electrostatics calculations, intramolecular electric fields, and how proteins conformationally respond to changes in electric fields, are also increasingly implicated in biophysical processes, from enzyme reaction mechanisms to voltage sensing in ion channels. Clearly, the excellent agreement of AMOEBA with DFT observed here does not negate the potential for inaccuracy in other systems or even alternative states along the CypA reaction pathway, but it does highlight the potential for polarizable MM models to achieve quantitative accuracy in biological environments where the electric field is crucial for structure or function.