What are the key factors governing the nucleation of CO hydrate?

Microsecond molecular dynamics simulations were performed to provide molecular insights into the nucleation of CO hydrate. The adsorption of sufficient CO molecules around CO hydration shells is revealed to be crucial to effectively stabilize the hydrogen bonds formed therein, catalyzing the hydration shells into hydrate cages and inducing the nucleation. Moreover, a high aqueous CO concentration is found to be another key factor governing the nucleation of CO hydrate, and only above a critical concentration can the nucleation of CO hydrate occur. The 456 cages, with size similar to the CO hydration shell and an elliptical space closely matching a linear CO molecule, play a dominant role in initiating the nucleation and remain the most abundant. The incipient CO hydrate is rather amorphous due to the abundance of metastable cages (mostly 456).