Methane hydrate - Melting and memory

We present the results of a long timescale molecular dynamics simulation of a methane hydrate/methane gas interface formed along the [001] hydrate surface. The simulations were performed at 15-20 degrees C above the stable hydrate temperature so that we were able to observe melting under conditions that were sufficiently gentle to allow any residual order associated with the memory effect for hydrate nucleation to be identified. The simulations have been analyzed using a set of novel order parameters designed specifically to quantify the microscopic molecular structure associated with the different phases of water. The simulations do show an enhanced level of ice- and clathrate-structure in the liquid water that forms when the hydrate decomposes, but there is no evidence of significant clusters of the ordered water.