Flatland The Periodic System for

Institute of Atomic and Molecular Physics, Jilin University, 130023 Changchun, PRC 

The serious scientific reason for the present work [1] was the idea that the dimensionality, D, could be regeirded us a variable around its usual physical value, D=3, and that this covdd yield deeper insight to the structure of the usual Periodic System. Alternatively, in systems like very anisotropic semiconductors, the real physics could be approximately of the D=2 type. 

On the more joculeir side, the starting point was a problem [2] in the 20th International Chemistry Olympiad, a teen-ager contest, where the participants were asked to construct the Periodic System for D=2, see Fig. 1-2. This supposedly correct answer was based on 

Roald Hoffmann has pointed out to us that the Bohr atom, a 2D model applied on the 3D world, works because the missing zero-point energy does cancel the wrong energy law of —(Z/ n — )), compared to —(Z/ny, for 2D and 3D, respectively. Note that the energy only depends on the principal quantum number, n = 1,2,3. in both 

In a broad sense, the science and technology of a two-dimensional universe, dubbed planiverse , has been discussed by Dewdney and others [13-15]. 

---