Multielectron photoexcitations in x-ray-absorption spectra of $4p$ elements

By removing the structural x-ray-absorption fine-structure signal from K-edge absorption spectra of 4pelements from Ga to Br in chalcogenide glasses and other samples, the pure atomic absorption is recovered. Its main components are shake-up and shake-off channels of the [1s3p] and [1s3d] group. The [1s3p]4p shake-up channel is observed to close off along the series as the 4p shell is progressively filled