Eigenvalues of Hückel systems of equivalent points

AbstractThree 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