Experimental and theoretical study of Al K-XANES in AIPO(4) (berlinite
) and in KAl(SO4)(2)12H(2)O(K-alum) with different types of Al environ
ment is performed. Calculations proved that the experimental XANES are
well reproduced within EXAFS-like approach to electron scattering des
cription i.e. considering the single-, double-and triple-scattering pr
ocesses on two and approximately linear three-atoms chains originated
at Al-absorbing atom and consisting mainly of O-atoms chosen under the
same for both compounds empirical ''selection rule''.