Figure 4: Two-dimensional carbon monoxide distributions.

The distribution of carbon monoxide molecules in sII clathrate from MD simulation: (a–c) carbon atoms in carbon monoxide in 5¹²6⁴ cages at 25, 100 and 260 K, respectively; (d–f) oxygen atoms in carbon monoxide in 5¹²6⁴ cages at 25, 100 and 260 K, respectively; (g–i) carbon atoms in carbon monoxide in 5¹² cages at 25, 100 and 260 K, respectively; (j–l) oxygen atoms in carbon monoxide in 5¹² cages at 25, 100 and 260 K, respectively; the intensities are projected on the a–b plane from around 10,000 carbon monoxide molecules. The cage centre is at coordinate (0,0), and the axial unit is Å. The intensity is the normalized density distribution of carbon monoxide in clathrate cages, and the summed total value is 1 in each cage.