Structural properties of bulk copper: Pseudopotential plane-wave-basis study

We have examined the structural properties of bulk copper within the body-centered-tetragonal (bct) crystal system using the pseudopotential plane-wave-basis scheme. By calculating the total energy as a function of c/a and volume, where a and c are in-plane and vertical lattice constants, we show that the bcc double minima and metastable bct phase, which were reported in the previous pseudopotential mixed-basis studies, are absent in the energy surface. Based on the calculated results, we suggest an alternative interpretation of a recent scanning tunneling microscopy experiment on Cu/Pd(100).