Using the method of molecular dynamics, the process of crack propagation in a single-crystal copper plate with a crack is simulated under the action of mixed loading corresponding to normal separation and transverse shear. A comprehensive study of the influence of geometric characteristics (model dimensions, crack length), temperature, strain rate and loading mixing parameter on the plate strength, crack growth and direction was carried out. The angles of propagation of a central crack in a copper plate are determined using the molecular dynamics method.