Two-center two-electron excitations identified in NEXAFS for solid Ne

Experimental K-edge NEXAFS (near-edge x-ray-absorption fine-structure) data for solid Ne are compared with theoretical results. Seven features in the experimental spectrum that are not reproduced by the one-electron theoretical results are found to be attributable to two-electron excitations. Five of them are usual one-center excitations, but the remaining two are found to be two-center excitations involving resonant orbitals as opposed to the usual bound orbitals. In contrast, two-center, two-electron excitations involving only bound orbitals are found to be absent in the experimental spectrum. {} 1996 The American Physical Society.