BONDING STATES IN Cu-O AND T1-O LAYERS OF T1₂ Ba₂ Ca₂ Cu₃ O₁₀

The electronic density of states of the known highest Tc material T1₂ Ba₂ Ca₂ Cu₃ O₁₀ has been calculated with tight-binding approximation. The bonding states in Cu-O and Tl-O layers are analysed. Because it has the electronic structures similar to that of La-oxides and Y-oxides, it is believed that they have the same leading superconducting mechanism.