We find that both AmberTools AM1-BCC and OpenEye AM1-BCC partial charge generation methods vary across hardware given the exact same input conformer (Figure ). While the majority of conformers produced similar charges across hardware with average maximal partial charge di erences of 0.002 e for AmberTools and OpenEye AM1-BCC charges, we observe di erences of up to 0.09 e using AmberTools AM1-BCC charges on di erent hardware platforms and di erences of up to 0.025 e using OpenEye AM1-BCC charges. We confirm that OpenEye AM1-BCC charges do not di er across repeat charges of the same conformer, but do di er across hardware (SI Figure ). However, we find that AmberTools AM1-BCC charges can di er across repeat charge calculations for the same conformer, so some of this partial charge discrepancy across hardware may come from di erences in the convergence of geometry optimization calculation (SI Figure ).