Abstract
An analysis of theoretical studies on the electronic structures and chemical properties of superheavy elements has been performed. It is noted that the specific features of calculations of molecular systems including superheavy element atoms are determined by the exceptional role of relativistic effects that should be taken into account at all stages of electronic structure modelling. The main approximations for relativistic Hamiltonians and general approaches to the solution of the many-electron problem for both superheavy element atoms and their compounds have been considered and compared. The results of modelling the chemical properties of superheavy elements by ab initio methods and density functional theory have been analysed.