  The impact of geometry on many body localization is studied on simple,
exemplary systems amenable to exact diagonalization treatment. The crossover
between ergodic and MBL phase for uniform as well as quasi-random disorder is
analyzed using statistics of energy levels. It is observed that the transition
to many-body localized phase is correlated with the number of nearest coupled
neighbors. The crossover from extended to localized systems is approximately
described by the so called plasma model.
