This JavaScript web page generates an energy diagram for simple Huckel Molecular Orbital systems. You can set up the determinant yourself or let the program do it by selecting specific compounds from the list. The rules for setting up the determinant are very simple:

  1. Construct an n-dimensional determinant, where n is the number of p orbitals from carbon atoms in the system.
  2. Place 'x' along the diagonal.
  3. Place '1' everywhere two carbons are adjacent. For example, if carbons 2 and 3 are adjacent, then put a 1 at (2,3) and at (3,2).
  4. Place '0' everywhere else.