Electronic Structure of CuCl 4 −3 , CuCl 4 −4 , and CuCl 4 −2 Clusters

Electronic properties are obtained of CuCl   4 −3 , CuCl   4 −4 , and CuCl   4 −2Clusters using the SCF Xα multiple‐scattered wave method. The calculation shows that the “cluster band gap energy” in the CuCl   4 −3clusters is 3.6 eV, fortuitously close to the experimental direct band gap of 3.4 eV of CuCl. Cu 0 in CuCl   4 −4introduces a “donor” level at V c − 0.3 eV. In CuCl   4 −2the energy levels corresponding to the upper valence bands of CuCl almost overlap and the energy gap widens substantially. The energy level 3t 2 with a hole is almost at the same level as that of 1t 1 of other clusters. A significant Cu 3d–Cl p hybridization is introduced in CuCl   4 −4 .