Articles you may be interested in Molecular dynamics of polymer crystallization revisited: Crystallization from the melt and the glass in longer polyethylene J. Chem. Phys. 139, 054903 (2013) Calorimetric data of primary crystallization is usually interpreted in the framework of the Kolmogorov ͓Dokl. Akad. Nauk SSSR 1, 355 ͑1937͔͒, Johnson and Mehl ͓Trans. AIME 135, 416 ͑1939͔͒, and Avrami ͓J. Chem. Phys. 7, 1103 ͑1939͒; 8, 212 ͑1940͒; 9, 177 ͑1941͔͒ ͑KJMA͒ theory. However, while the KJMA theory assumes random nucleation and exhaustion of space by direct impingement, primary crystallization is usually driven by diffusion-controlled growth with soft impingement between the growing crystallites. This results in a stop of the growth before the space is fully crystallized and induces nonrandom nucleation. In this work, phase-field simulations are used to check the validity of different kinetic models for describing primary crystallization kinetics. The results show that KJMA theory provides a good approximation to the soft-impingement and nonrandom nucleation effects. Moreover, these effects are not responsible of the slowing down of the kinetics found experimentally in the primary crystallization of glasses.