  We develop a numerical method, which allows to find pairs of metastable
states differing by transition of several electrons. We show that at low
temperature these pairs can be treated as local metastable systems that
determine low-frequency properties of Coulomb Glass with low external disorder.
The contribution of these pairs to low-frequency properties is suppressed when
the strength of the external disorder becomes comparable with interaction
between neighboring electrons.

Disordered Systems and Neural Networks