  The thermal properties of bulk copper are investigated by performing ab
initio DFT and DFPT calculations and using the quasiharmonic approximation for
the free energy. Using both the LDA and the GGA for the exchange-correlation
potential, we compute the temperature dependence of the lattice constant,
coefficient of thermal expansion, bulk modulus, pressure derivative of the bulk
modulus, phonon frequencies, Grueneisen parameters, and the electronic and
phonon contributions to the specific heats at constant volume and constant
pressure. We obtain answers in closer agreement with experiment than those
obtained from more approximate earlier treatments. The LDA/GGA errors in
computing anharmonic quantities are significantly smaller than those in
harmonic quantities. We argue that this should be a general feature, and also
argue that LDA/GGA errors should increase with temperature.
