ANDERSON TRANSITION AND CRITICAL-LEVEL STATISTICS IN 2.58 DIMENSIONS

We present numerical scaling results for the critical localization pro perties of electrons in disordered tight-binding systems on a bifracta l lattice geometry of dimension d=1+ln3/ln2. The Anderson metal-insula tor transition is demonstrated and the localization-length critical ex ponent nu approximate to 2.2 is estimated. At the transition the neare st level spacing distribution function P(S) is shown to follow a scale -invariant curve describing the critical spectral-density fluctuations . Our results are discussed in connection to disordered polymeric mate rials and to field theories in 2+epsilon dimensions.