SEARCH Articles Figures Tables Hohenberg theorems Hohenberg-Kohn Hohenberg-Kohn principle Hohenberg-Kohn theorem Kohn Kohn variational principle Second variation THE THEOREM The Hohenberg-Kohn Theorem The Hohenberg-Kohn Variational Theorem The Second The Variational Principle The second principle The variation theorem Variation principle Variation theorem Variational principle Variational theorem