TiC: A stable T -symmetry hollow cage.

A stable T -symmetry TiC cage was systemically investigated using density functional theory. The structure of TiC is a hollow cage with twelve TiC subunit of three pentagons and one hexagon. The calculated frequencies are in the range 95.

Cu20Si12: A Hollow Cage Constituted of a Copper Dodecahedron and a Silicon Icosahedron.

A stable hollow copper silicide cage with Ih symmetry, Cu20Si12, constituted of a copper dodecahedron and a silicon icosahedron, was investigated using density functional theory. Molecular dynamics simulations show that Cu20Si12 retains its geometric topology up to an effective temperature of about 962 K. The molecule has a HOMO-LUMO gap of 1.