  Semilocal density functionals for the exchange-correlation energy are needed
for large electronic systems. The Tao-Perdew-Staroverov-Scuseria (TPSS)
meta-generalized gradient approximation (meta-GGA) is semilocal and usefully
accurate, but predicts too-long lattice constants. Recent "GGA's for solids"
yield good lattice constants but poor atomization energies of molecules. We
show that the construction principle for one of them (restoring the density
gradient expansion for exchange over a wide range of densities) can be used to
construct a "revised TPSS" meta-GGA with accurate lattice constants, surface
energies, and atomization energies for ordinary matter.
