When explaining the mathematics behind calculating molecular orbital energy , namely HOMO and LUMO energies, using quantum chemistry, Chainer Chemistry documentation states that
From mathematical viewpoint it requires a solution of an internal eigenvalue problem for a Hamiltonian matrix.
- I have never heard of internal eigenvalue problem in mathematics. Is this a term specific to quantum chemistry and what it means?
- Is the Hamiltonian matrix same as Kohn-Sham Hamiltonian?