While complete reparameterization of the repulsive potential functions might seem an intuitive approach, such modification would affect all chemical interactions involving C-H and C-C pairs across diverse molecular environments, potentially compromising DFTB3's es-tablished accuracy for standard chemical structures. Our targeted approach using LCHFs allows precise modification of the repulsive potentials within specific distance ranges relevant to hydride transfer reactions without disrupting the well-validated performance of DFTB3 for equilibrium structures. This strategy follows similar approaches in the literature, such as the addition of Gaussian functions (GFs) in specific distance ranges as perturbations to the RPFs to improve O-H interactions in water simulations and the modification of O-P repulsive potentials in the OPhyd parameterization. Although this approach is somewhat empirical in nature and represents an ad-hoc solution to the problem, it offers the advantage of enabling a more systematic analysis of how the hydride transfer barrier depends on the magnitude of the perturbation applied to the repulsive potential. Formally, the harmonic functions (HF) proposed in this work are defined as: