  The use of electric fields applied across magnetic heterojunctions that lack
spatial inversion symmetry has been previously proposed as a non-magnetic mean
of controlling localized magnetic moments through spin-orbit torques (SOT). The
implementation of this concept at the single-molecule level has remained a
challenge, however. Here, we present first-principle calculations of SOT in a
single-molecule junction under bias and beyond linear response. Employing a
self-consistency scheme invoking density functional theory and non-equilibrium
Green's function theory, we compute the current-induced SOT. Responding to this
torque, a localized magnetic moment can tilt. Within the linear regime our
quantitative estimates for the SOT in single-molecule junctions yield values
similar to those known for magnetic interfaces. Our findings contribute to an
improved microscopic understanding of SOT in single molecules.
