https://www.nist.gov/publications/final-state-rule-vs-bethe-salpeter-equation-deep-core-x-ray-absorption-spectra-0
The independent-electron approximation together with the final-state rule provides a well established method for calculating x-ray absorption spectra that takes
finalstaterulevsbethe
https://www.vedantu.com/question-answer/emission-and-absorption-spectra-explain-the-class-12-physics-cbse-5f7165f5dc480e2a5cdf39b8
What is emission and absorption spectra Explain the different types of emission and absorption spectra with examples Diagram not necessary
absorption spectraemissionexplainclass