In keeping with our goal of deriving force field parameters directly from QM, rather than fitting to experiment, we have supplemented the atoms-in-molecule non-bonded parameters with harmonic bond and angle parameters derived directly from the QM Hessian matrix. There are a number of methods available for deriving bonded parameters from the QM Hessian matrix, but our recent adaptation of the Seminario method (which we name the modified Seminario method) is conceptually quite straightforward whilst yielding parameters that reproduce QM vibrational frequencies with a mean unsigned error of 49 cm -1 , below that of OPLS (59 cm -1 ). Collectively, we have named these methods the QUantum mechanical BEspoke (QUBE) force field. This name reflects the fact that force field parameters are derived by the user specifically for the small molecule under study, directly from QM calculations. We have released a software toolkit (QUBEKit) that facilitates the derivation of small organic molecule force field parameters, and also allows the user to derive the positions of off-site charges to model anisotropic electron density and to fit dihedral parameters to QM torsion scans. QUBE force fields have been derived for 109 small organic molecules, and yield mean unsigned errors of 0.024 g/cm 3 , 0.79 kcal/mol and 1.17 kcal/mol in computed liquid density, heat of vaporization and free energy of hydration. These results are competitive with standard transferable force fields, which have been extensively fit to properties such as these.