[en] Highlights: • A new Xe-SiC potential is developed • Swelling is mostly due to intrinsic point defects contributions • Swelling can be estimated from the sum of individual defect relaxation volumes • Strain reduction during annealing comes from dynamic recombination of defects - Abstract: Atomistic calculations using a newly developed Xe-SiC interatomic potential are carried out to determine the contributions of point defects to the strain build up in Xe implanted 4H-SiC. Relaxation volumes for individual point defects are calculated, and analysed in comparison to the swelling determined in a simulation including a large homogeneous distribution of these defects. These investigations confirm the negligible influence of the implanted gas, with the swelling mostly originating from intrinsic point defects generated by implantation. Using experimental swelling data, possible point defects distributions are determined as a function of the dose. Strain reduction during annealing simulations is shown to be due to dynamic recombination of point defects, with an estimated activation energy in excellent agreement with experiments.