Band picture of the spin-Peierls transition in the spin-1/2 linear-chain cuprateGeCuO3

The results of electronic-structure calculations for ${\mathrm{GeCuO}}_3$ feature a pair of narrow (∼1 eV) half-filled, one-dimensional ${\mathrm{\sigma }}^{\mathrm{*}}$ conduction bands that originate from two edge-sharing ${\mathrm{CuO}}_2$ linear chains in the orthorhombic cell. Unusual transport properties are predicted since the confined carrier motion along the chains (at any band filling) requires tunneling through nodal charge-density regions. At the spin-Peierls transition, the dimerization of the ${\mathrm{CuO}}_2$ chains can open a band gap at ${\mathit{E}}_{\mathit{F}}$, provided that the Cu displacements in neighboring chains are staggered.