The physical model of water-like particles in two dimensions

The physical model of water-like particles in two dimensions 

Each particle is depicted as a disk having three arms emanating from the center and pointing towards the vertices of an equilateral triangle. This is a reduction of the tetrahedral model described in Fig. 1.9, where the arms point to the four vertices of a regular tetrahedron. 

The intermolecular interaction is a superposition of two functions a Lennard-Jones type, which depends only on the intermolecular distance R, and a hydrogen bond-like (HB) part, which depends on both the distance and the relative orientations of the two particles. An HB is formed whenever one arm of a particle points to the center of a second particle and aligns with 

Strong binding energy High iocai density 

Weak binding energy High local density 

---