JKFit sets for use with diffuse augmented correlation consistent orbital basis sets, often denoted aug-cc-pVnZ and aug-cc-pV(n+d)Z, were created by augmenting the cc-pV(n+d)Z/JKFit sets detailed above with an additional exponent for each orbital angular momentum shell. The exponents were determined using the even- The MAE due to density fitting with the auxiliary basis sets developed in this work is compared to that from using the cc-pVnZ/JKFit auxiliary sets in Table for negligible errors in the density fitting for all molecules considered. Table indicates that the cc-pV(D+d)Z/JKFit auxiliary basis, which adds only a single set of f-type functions, provides only a modest improvement over cc-pVDZ/JKFit. This raises the question of how the accuracy of the density fitting could be improved, and whether such improvements offset any increased computational effort they would require. As the TZ-5Z auxiliary sets add both additional f-and g-type functions, we investigate the effect of adding a single set of g-type functions to the cc-pV(D+d)Z/JKFit auxiliary basis [denoted cc-pV(D+d)Z+1g/JKFit herein]. This g-function takes the exponent of the new g-function added to cc-pV(T+d)Z/JKFit auxiliary basis without any re-optimisation, and results in a MAE of 0.25528 mE h over the test set of molecules, compared to the value of 0.36047 mE h for cc-pV(D+d)Z/JKFit. The standard deviation and MAX (see Supporting Information) are also reduced, but the improvements are small compared to the orbital BSIE (∼88.5 mE h ) and the increase in computational effort of including a higher orbital angular momentum shell does not appear warranted for HF calculations of molecular energies.