Eigenvalues of Hückel systems of equivalent points Original Research Article

Three methods of solving secular equations for highly symmetric systems are compared. In the matrix method, coset and double coset expansions with subduction-adapted basis sets give maximum benefit for sub-regular orbits. Reduction to characters takes an especially simple form for a framework that spans the regular orbit of a point group. Both these and the lattice group method are intimately linked to the work of Frobenius on group determinants.