Photoemission spectra and band structures ofdband metals. IX. Triangulation analysis of angle-resolved data on copper

Copper is used as a test case in the evaluation of the triangulation method for the determination of the electronic band structure over extended regions of $\overrightarrow{\mathrm{k}}$ space. High-resolution angle-resolved-photoemission spectra were taken systematically on the (100) and (110) faces, and the energy-coincidence criterion was used to identify the same transition on each face and thereby fix absolutely the values of $\overrightarrow{\mathrm{k}}$. The pitfalls of the energy-coincidence criterion are pointed out. The experimentally derived bands are compared, through the mediation of a combined interpolation scheme, with the first-principles calculations of Burdick, and are found to be in excellent agreement after inclusion of spin-orbit splitting in the $d$ bands. Other, less systematic, features are interpreted variously as secondary-cone emission, density-of-states features, or surface-state emission.