Abstract
We report metal-encapsulated caged clusters of silicon from ab initio pseudopotential plane wave calculations using generalized gradient approximation for the exchange-correlation energy. Depending upon the size of the metal ( ) atom, silicon forms fullerenelike , , Zr, and cubic , , Ru, Os, caged clusters. The embedding energy of the atom is due to strong interactions that make the cage compact. Bonding in these clusters is predominantly covalent and the highest-occupied–lowest-unoccupied molecular orbital gap is . However, an exceptionally large gap (2.35 eV) is obtained for Frank-Kasper polyhedron. Interaction between these clusters is weak, making them attractive for cluster-assembled materials.
- Received 20 April 2001
DOI:https://doi.org/10.1103/PhysRevLett.87.045503
©2001 American Physical Society