Nuclear Magnetic Resonance and Nuclear Quadrupole Resonance Study of181Ta in The Commensurate Charge Density Wave State of 1T-TaSe2

The first systematic study of nuclear magnetic resonance (NMR) and nuclear quadrupole resonance (NQR) of the 181 Ta nuclei has been made on 1 T -TaSe 2 at 4.2 K in order to get detailed information on the superlattice structure in the commensurate charge density wave state of this material from a microscopic viewpoint. The NMR and NQR spectrum show seven fairly sharp resonance lines, six of which are strong and one is weak. The results are discussed on the basis of the star-shaped cluster model with an emphasis on the fine structures due to the three-dimensional ordering of clusters.