We have derived orbital basis sets from scattering theory. They are express
ed as polynomial approximations to the energy dependence of a set of partia
l waves, in quantized form. The corresponding matrices, as well as the Hami
ltonian and overlap matrices, are specified by the values on the energy mes
h of the screened resolvent and its first energy derivative. These orbitals
are a generalization of the third-generation linear muffin-tin orbitals an
d should be useful for electronic-structure calculations in general.