This work provides a generalization of Evans' homogeneous nonequilibrium method for estimating thermal conductivity to molecular systems that are described by general multibody potentials. A perturbed form of the usual Nose-Hoover equations of motion is formally constructed and is shown to satisfy the requirements of Evans' original method. These include adiabatic incompressibility of phase space, equivalence of the dissipative and heat fluxes, and momentum preservation.