Abstract
Magnetic excitations of various kinds possible within the Emery model are studied in the present paper. It is shown that the formation of polaron-type excitations is favourable for two holes with aligned spins (triplet). The exchange coupling J increase leads to the formation of a large-size triplet bipolaron. If hole spins are antiparallel, a bound s-type singlet is probably always formed and the decrease in J causes an increase in the localization radius.