Solid phase epitaxial regrowth of pre-amorphizing implants has received significant attention as a method to achieve high dopant activation with minimal diffusion at low implant temperatures and suppress channelling. Therefore, a good understanding of the amorphization and regrowth mechanisms is required in process simulators. We present an atomistic amorphization and recrystallization model that uses the interstitial–vacancy (I–V) pair as a building block to describe the amorphous phase. I–V pairs are locally characterized by the number of neighbouring I–V pairs. This feature captures the damage generation and the dynamical annealing during ion implantation, and also explains the annealing behaviour of amorphous layers and amorphous pockets.