  We report a numerical study of thermo-osmotic slip, i.e. the particle flux
induced by a thermal gradient along a solid-fluid interface. To facilitate
comparison with theory, we consider a model of an ideal but viscous gas. We
compare three numerical routes to obtain the slip coefficient: 1. by using the
Onsager reciprocity relations 2. by using the appropriate Green-Kubo relation
3. via the excess enthalpy. The numerical results are found to be mutually
consistent, and to agree with the theoretical prediction based on the
assumption that hydrodynamics and thermodynamics are locally valid.
