  We report on Cu nuclear quadrupole resonance (NQR) and NMR studies of an
optimally hole-doped superconductor Ca2-xNaxCuO2Cl2 (Tc ~ 28 K for x ~ 0.2). In
spite of robust oxygen composition, we observed a multiple broad NQR frequency
spectrum and nonexponential Cu nuclear spin-lattice relaxation, being similar
to those of La2-xSrxCuO4-d.
