Comment on Density and Physical Current Density Functional Theory by Xiao-Yin Pan and Viraht Sahni, Int. J. Quant. Chem. 110, 2833 (2010)

This comment criticizes the above paper by Xiao-Yin Pan and Viraht Sahni. It is shown that their formulation of Physical Current Density Functional Theory is, at best, a garbled reformulation of the Vignale-Rasolt current-density functional theory, and, at worst, a potential source of mistakes insofar as it complicates the formulation of the variational principle and prevents the constrained search construction of the universal functional.