They’re not poker-related, but the ICM algorithm models these things as iteratively constructed trees. The internal coordinates of these systems can be represented as Z-matrices. These systems are encoded via ASCII (“ASS-kee”) strings in SMILES notation. (-5[1])Three lines meet at a point in front of a circle in a representation of these things called the Newman projection. A field (10[1])of “mechanics” named for these systems calculates interactions between them via the Lennard-Jones potential. A line-angle formula represents the “skeleton” (10[1])of these things, which are commonly represented using ball-and-stick models (10[1])in classroom (10[1])demonstrations. For 10 points, materials and computational sciences often study the modeling of what systems composed of atoms? ■END■ (10[3])