The 2p X-ray absorption spectra of 3d transition metal compounds measu
red with fluorescence yield (FY) appear distorted. It is shown that th
is distortion is intrinsic to FY detection and not due to self-absorpt
ion. It results from the final-state dependent variation of the fluore
scence decay, which is more than 400%. The Auger decay is also final-s
tate dependent but the variation is only 25%. In the approximation tha
t the final states do not interfere with each other (which is shown to
be approximately correct for Ni2+), the FY spectral shape identifies
with the X-ray absorption spectrum multiplied with its symmetry-depend
ent fluorescence decay. Results are given for the nickel 2p edge of Cs
[NiCr(CN)6]. 2H(2)O measured synchronously with FY and electron yield.