and it‘s applications have attracted much attention in the last years, as it is well-known [@Wakabayashi1]. In this paper, it is proposed for an approach based on the use of closed clusters (CC) to calculate the energy band structure of graphene. We have developed this approach earlier in application to the one-dimensional and three-dimensional crystals with diamond structures [@Tal1]. The essence of the CC approach is to bring together all bonds of atoms which are located on the edge of a cluster in order to eliminate the “dangling” bonds. This approach is found to be especially useful for calculation of the energy spectrum of crystals with point defects, such as vacancies or impurity atoms. The simplest and most widespread approach to calculate such impurity states is known to be the effective mass method. This approximation works sufficiently well in cases of impurity levels being located along the borders of the energy zones. However, it is inapplicable to the description of so-called “deep levels”, which lie far from the zone borders [@Lannoo]. One of the methods used for those levels is the cluster approach, in which a group of atoms - the cluster - is mentally picked from a crystal lattice.

