A crucial step in building any FF stands in the selection of the ICs used to represent the PES of the target molecule. In this respect, the previous versions of JOYCE code provided a list of all possible ICs for the target molecule, and the initial, time-consuming step consisted in a manual classification and selection of the ones to retain. Although a 'black-box' strategy that retains all internal coordinates (ICs) might seem like the simplest option as it requires no user intervention, it can lead to overfitting issues due to the non-orthogonal and highly redundant nature of a basis set consisting of all ICs. In JOYCE3.0, once the atom types to be employed in the QMD-FF have been defined, the new code provides a preliminary list of all ICs (based on the optimized QM geometry) specifically classified in terms of bond stretching, angle bending, dihedrals and non-bonded distances and proposes options for a further refinement. Specifically, the ICs automated selection occurs by: i) identifying the connectivity within the molecule, determined using Pauling bond orders, and assessing the resulting covalent bond lengths based on whether the distance is no more than 30% longer than the sum of the covalent radii of the involved atoms.