|$D(E)$ [1028 eV-1m-3]|
The density of states for copper was calculated using the program Quantum Espresso (version 4.3.1). The Fermi energy is at $E=0$. This calculation includes the 3d and 4s bands. There are 11 electrons in these bands for copper. The lattice constant is 3.61 Å and there are 4 atoms in a conventional unit cell. The volume of the primitve unit cell is 3.61³/4 Å³ = 1.176147 × 10-29 1/m³. The Fermi energy is at $E=0$.