Max-Planck Institut fuer Festkoerperforschung, Stuttgart, D-70569, Germany

The compd. Cs3Te22 is well-known for its interesting structural features. It contains both a unique 2,3-connected defect square Te sheet and Te8 rings. For a better understanding of the structure and bonding, the band structure of Cs3Te22 is examd. by means of the ab initio tight-binding linear muffin-tin orbital (TB-LMTO) method, which is based upon d. functional theory (DFT). The calcns. are complemented by an anal. of the electronic d. topol. with the electron localization function (ELF) and a traditional orbital anal. using the projected d. of states (DOS) and the crystal orbital Hamiltonian population (COHP). Our study indicates that the short Te-Te contacts between Te8 rings and the defect Te63- sheet in this compd. have a direct influence upon the properties of this material. The presence of this interaction perturbs the electronic d. relative to that which one obtains from anal. of the isolated defect sheet and leads to favorable conditions for an insulator state.
 

Inorganic Chemistry, 37 2351-2357, 1998.