▎ 摘　　要

The effect of the linear approximation of the electronic spectrum of single-layer graphene (low-energy approximation) on the magnitude of charge transfer between an adatom and graphene has been investigated. It has been shown that the implementation of this approximation for adsorption of alkali metals and halogens leads to a change in the occupation numbers of local and band states as compared to the results obtained in the model taking into account the entire spectrum. However, the total occupation numbers agree quite well.