The band structure of copper has been calculated using a modified plane-wave method. Use is made of the explicit inclusion of a $d$ orbital in the set of base states. Results along the [001], [110], and [111] directions are reported. These results are in good agreement with other calculations. An extension of the pseudopotential method, based on the success of the calculation, is suggested.

• Received 29 October 1968

DOI:https://doi.org/10.1103/PhysRev.180.744