In such a crystal the atoms would rotate and return to their original location — repeating in time as well as space. (newscientist.com)
There actually is no such thing as too low a temperature for some sort of ice crystal to form and for such crystals to settle out and land on the surface. (scientificamerican.com)
Although researchers are trying to drill such crystals with beams of ions, none have succeeded yet. (newscientist.com)