DETERMINATION OF OBSERVABLE CONDUCTION-BAND SYMMETRY IN ANGLE-RESOLVED ELECTRON SPECTROSCOPIES - NON-SYMMORPHIC SPACE-GROUPS

In angle-resolved photoemission, selection rules restrict the observable final state symmetry. The rules for the initial state in inverse photoemission are the same. For cubic groups they are known. In non-symmorphic space groups new rules apply. The authors show how to determine the observable final states for this class of space groups and work out explicitly the example of the graphite structure. The mathematical concepts are supported by direct experimental evidence obtained in normal photoemission from graphite.