Abstract
Well-localized orbitals belonging to a single Landau level are shown to obey certain identities. The results apply both to an infinite plane and to the case when the wave function obeys boundary conditions. The number of identities or sum rules for each kind of localized orbitals is determined by the number of zeros of the corresponding kq-function. As a consequence of the identities it follows that the well-localized orbitals are linearly dependent. In the infinite case they nevertheless form a complete set. For the finite lattice the set becomes undercomplete.