Hydrates are a possibility in oil/gas exploration, production, transportation, or processing, which involves water and molecules smaller than n-pentane. When small ( 9 Å) nonpolar molecules contact water at ambient temperatures (typically 100 F) and moderate pressures (typically 180 psia), a water crystal form may appear--a clathrate hydrate. These individual polyhedra then combine to form specific crystalline lattices. Such solids can be formed with N2, H2S, CO2, C1, C2, C3, and iso-butane. Larger molecules like n-butane and cyclopentane require the presence of some smaller molecules.