  The nucleation of gas hydrates is of great interest in flow assurance, global
energy demand, and carbon capture and storage. A complex molecular
understanding is critical to control hydrate nucleation and growth in the
context of potential applications. Molecular dynamics is employed in this work
combined with the mechanical definition of surface tension to assess the
surface stresses that control some of the behavior at the interface. Ensuring
careful sampling and simulation behavior, this work extracts meaningful results
from molecular properties. We characterize the interfacial tension for sII
methane/ethane hydrate and gas mixtures for different temperatures and
pressures. We find that the surface tension trends positively with temperature
in a balance of water-solid and water-gas interactions. The molecular dipole
shows the complexities of water molecule behavior in small, compressed
pre-melting layer that emerges as a quasi-liquid. These behaviors contribute to
the developing knowledge base surrounding practical applications of this
interface.
