AbstractA new mode of reorientation of the field of director $$\hat n$$ n ^ of a nematic liquid crystal (LC) encapsulated into a rectangular cell under strong crossed electric ( E ) and magnetic ( B ) fields has been proposed. Numerical calculations performed within the linear generalization of the classical Ericksen–Leslie theory show that transition periodic structures facilitating a decrease in the effective rotational viscosity of a nematic, formed by 4- n -pentyl-4'-cyanobiphenyl (5CB) molecules, may arise during reorientation of $$\hat n$$ n ^ at certain ratios of the moments and momenta per unit volume of the LC phase and when E ≫ E _th. The calculations conducted for 5CB also indicate that the periodic structures formed in a LC cell facilitate a decrease in reorientation time τ_on of the director field.