Interplane coupling in the quasi-two-dimensional 1<i>T</i>-TaS₂

Density-functional band-structure calculations including atomic displacements in the charge-density wave phase have been performed for the layered 1<i>T</i>-TaS₂. This quasi-two-dimensional material exhibits a charge-density wave extending in all three dimensions. We find that the topmost occupied Ta <i>d</i> band is localized in plane but strongly disperses perpendicular to the layers showing favorable nesting conditions in <i>z</i> direction. The calculations are compared to angle-resolved photoemission experiments and possible consequences on the temperature behavior of the resistivity are discussed.