For example, at long times, the isochoric simulations develop negative pressures, which likely hinders these simulations from crystallizing to the same extent as the isobaric NPT simulations. At the same time, the difference between the NVT and NVE simulations likely relates to the substantial heating that takes place as nucleation proceeds in the NVE simulations (see Fig. ). Therefore, heat release and variations in system density during polymer crystal formation likely influence the long-time kinetics of crystal growth, but do not appreciably impact molecular-level structural details of small crystal nuclei. With respect to alkane and polymer crystallization, there has been some discussion as to whether densification precedes local orientational ordering (i.e., what Anwar et al. call crystallinity), or local orientational ordering precedes densification. Russo and Tanaka's recent review on crystal nucleation highlights how the latter is generally operative during crystallization in colloidal and other spherical particle systems. The fact that this study's isochoric nucleation simulations (i.e., NVT and NVE simulations) yielded early-stage PE crystal nuclei that were structurally indistinguishable from those arising from the isobaric NPT simulations provides further evidence that orientational ordering precedes densification during PE nucleation under long-chain, high-driving force conditions. However, a detailed analysis of local densities and ordering is still warranted, and such work is currently underway.