Excellent catch, Rebecca! I've updated the function to include Newton's corrections for the quantum gases as you suggested. The new version now also accepts arrays as inputs. The improved function will be up as soon as the File Exchange administrators approve it. Thanks for sharing your expertise!
As a Chemical Engineering student, I've found this to be a great help. My only issue (after only using this a few times) is that Newton's Corrections weren't taken into consideration for helium and hydrogen. (Tc adjusted = Tc + 8K ; Pc adj = Pc + 8.106 bar) Otherwise, choice function!