The Electronic Structure of the Cronstedtite Layer

Ľubomír Benco and Ľubomír Smrčok
Institute of Inorganic Chemistry, Slovak Academy of Sciences 842 36 Bratislava, Slovakia

Abstract: The bonding in a cronstedtite layer was studied using a ninefold ordered supercell band structure calculation. The tight-binding scheme based upon the extended Hückel method was used to predict the electronic structure. The size of the problem was 162 atoms with 798 valence orbitals. The calculation showed different orbital interactions of oxygen p-orbitals with neighboring atoms with respect to the position in the layer. Substitution of Fe for Si in the terahedra reduced the role of the valence p-orbitals of the central Fe atoms. The d-orbitals of Fe were split in accordance with the rule of t2g-eg splitting. Although the density of states at the Fermi level was high, the partially filled 3d-bands were too narrow to permit normal metallic conduction.

Key Words: Bandstructure • Cronstedtite • Density of states • Electronic structure • Extended Hückel method

Clays and Clay Minerals; February 1995 v. 43; no. 1; p. 8-13; DOI: 10.1346/CCMN.1995.0430102
© 1995, The Clay Minerals Society
Clay Minerals Society (www.clays.org)