Na-23 and Si-29 NMR Knight shifts in the silicon clathrate Na16Cs8Si136 - art. no. 033102

Large Na-23 and Si-29 Knight shifts are observed for the silicon clathrate Na16Cs8Si136 in magic angle spinning NMR experiments. Electrical conductivi ty measurements on cold-pressed samples of the material also indicate metal lic behavior, with a room temperature value of rho approximate to 41 m Omeg a cm. An ab initio calculation of the s-projected density of states at the Fermi level leads to a simple interpretation of the distinct resonances obs erved for each of the three framework sites in Si-29 NMR experiments.