7 Mar 2001

• Alejandro Lopez-Castillo (10 Mar 2001): I read recently some parts of your e-book and liked very much. I read some your articles about cycle expansions and all of Wintgen's helium atom articles. Recently, I have studied some special 2-D periodic orbits of the hydrogen molecule (Bohr and Langmuir orbits) [see PRL 77 (1996) 4516 and PRA 58 (1998) 1846] starting from Bohr's work on the hydrogen molecule.

  I attempted a semiclassical quantization with a few PO's. The 1-D PO of hydrogen molecule is very similar to eZe and Zee configurations of helium atom. The hydrogen molecule is more complex than the helium atom since the spherical symmetry is broken. Now I am calculating the 1-D hydrogen molecule in axial and pendular configurations.

  It is known that the hydrogen molecule is a important system to understand the chemical bond, the three-body and four-body problems. It is a chaotic system where the classical, semiclassical and quantum aspects are important. And because of that, I ask that you include a discussion of that system in your book, if possible.

• Predrag: We are so far behind with other sections of the book that this will not happen anytime soon, to be realistic. However, what I can do very easily is to add a contributed section to the ChaosBook extras homepage and link the contributed text to the helium quantization chapter of the main text. Do you want to give it a try? If we like it and it fits well into the flow of the book it might eventually migrate into the text proper.