Evaluation and reparameterization of previously reported ReaxFF parameters (Jarvi, T. T.; et al. J. Phys. Chem. A 2011, 115, 10315-10322) is carried out for Au-S-C-H systems. Changes in Au-S and Au-Au bond parameters and S-Au-S angle bending parameters yield improvements for bond bending potential energy surfaces. The new ReaxFF parameters lead to good agreement with density functional theory geometries of small clusters and gold-thiolate nanoparticles. The energies of Au-38(SCH3)(24) clusters are compared, and the new ReaxFF calculations are also in good agreement with PBE calculations for the isomer orderings. In addition, the relative energies of Au-40(SCH3)(24) nanoparticles and Au-thiolate SAMs are calculated using the updated parameters. These new ReaxFF parameters will enable the study of the geometries and reactivity of larger gold-thiolate nanoparticles.