In the paper "Generalized Gradient Approximation Made Simple" by John P. Perdew, Kieron Burke, and Matthias Ernzerhof, several corrections are noted: 1. For the molecules Be₂, F₂, and P₂, the unrestricted Hartree-Fock solution breaks singlet spin symmetry, while the density-functional solutions do not. The UHF atomization energies for these molecules are +7 kcal/mol, −20 kcal/mol, and +41 kcal/mol, respectively, with a mean absolute error of 69.8 kcal/mol. 2. The PBE correlation energy for two-electron ions with nuclear charge Z → ∞ should be corrected to −0.0479 hartree, consistent with the PBE value ω = 0.046644 stated in the Letter. The previously quoted value of −0.0482 hartree was obtained from a more refined ω = 0.046920 from G. G. Hoffman's work. 3. Reference [6] should be "A. C. Scheiner, J. Baker, and J. W. Andzelm, J. Comput. Chem. (to be published)."In the paper "Generalized Gradient Approximation Made Simple" by John P. Perdew, Kieron Burke, and Matthias Ernzerhof, several corrections are noted: 1. For the molecules Be₂, F₂, and P₂, the unrestricted Hartree-Fock solution breaks singlet spin symmetry, while the density-functional solutions do not. The UHF atomization energies for these molecules are +7 kcal/mol, −20 kcal/mol, and +41 kcal/mol, respectively, with a mean absolute error of 69.8 kcal/mol. 2. The PBE correlation energy for two-electron ions with nuclear charge Z → ∞ should be corrected to −0.0479 hartree, consistent with the PBE value ω = 0.046644 stated in the Letter. The previously quoted value of −0.0482 hartree was obtained from a more refined ω = 0.046920 from G. G. Hoffman's work. 3. Reference [6] should be "A. C. Scheiner, J. Baker, and J. W. Andzelm, J. Comput. Chem. (to be published)."