Our initial identification of this artifact arose because computed B3LYP-D3 properties for hydrogen binding to a sequence of metal substitutions within the MFU-4l metal-organic framework contradicted chemical intuition. During an investigation of H2 binding enthalpies to different Kuratowski-type clusters, we noticed that the enthalpies of adsorption for the NiKur cluster were abnormally high. Specifically, the binding enthalpy to Ni I was smaller than that to Cu I , which is chemically unexpected. Due to d-orbital contraction moving from left to right across the periodic table, π-backdonation becomes less favorable. Based on this reasoning, H2 binding to Ni I should be stronger than to Cu I . From the investigation of thermodynamic properties, we found that H2-NiKur-(2) exhibited significantly larger ZPE values than all other clusters considered, with the difference being ~13 kJ/mol. Closer examination revealed that the H2-Ni translational mode had an artificially high frequency and was significantly mixed with the H2 stretch modes. These ill-behaved vibrations led to the underestimation of binding enthalpies for H2-NiKur-(2).