Abstract
Characters of generalized eigenvalue problem in FMO-MO method, which is one of the fastest methods to calculate molecular orbitals of large molecules such as proteins, are described in order to solve it efficiently. Fock matrix to solve looks dense, because 7.6% of elements have significant value even for a large molecule. The frontier orbital energies can be estimated from fragment and fragment-pair orbital energy distributions in FMO method, which is performed in FMO-MO calculation, and then the frontier orbitals can be obtained efficiently by the method to solve eigenvalue problem in a specific energy region.
