EVIDENCE FOR A NEW CLASS OF SOLIDS - FIRST-PRINCIPLES STUDY OF K(AL-13)

The stability of the crystalline phase of a cluster-assembled solid K( Al-13) has been investigated using first-principles total energy calcu lations. We find that K(Al-13) may form in the CsCl structure with a l attice constant of 6.52 Angstrom. Unlike the gas phase, in which the g round state of the Al-13 cluster is icosahedral, the Al,, becomes cubo ctahedral in the solid phase due to crystal field effects. The system is metallic and is stable against lattice distortions. The calculation s suggest that a new metastable solid could be made from two immiscibl e elements through specially designed synthesis processes.