The fact that PE crystal nucleation under high-driving force, long-chain conditions arises from local rearrangements, rather than chain-level rearrangements, is consistent with Luo and Sommer's findings based on polyvinyl alcohol simulations that polymer crystal nucleation appears to proceed in areas of increased local entanglement length. In particular, the similarities between the NPT, NVT, and NVE nucleation simulations can be interpreted as indicating that specific local environments in metastable polymer melts (such as those with increased local entanglement lengths) strongly favor and guide polymer crystal nucleation such that heat release and density variations during crystal nucleation have minimal effects on the early stages of the crystallization process.