<i>Ab initio</i>x-ray absorption study of copper<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>K</mml:mi></mml:math>-edge XANES spectra in Cu(II) compounds

Abstract

This work reports a theoretical study of the x-ray absorption near-edge structure spectra at the Cu $K$ edge in several Cu(II) complexes with $N$-coordinating ligands showing a square-planar arrangement around metal cation. It is shown that single-channel multiple-scattering calculations are not able to reproduce the experimental spectra. The comparison between experimental data and ab initio computations indicates the need of including the contribution of two electronic configurations ($3{d}^{9}$ and $3{d}^{10}L$) to account for a proper description of the final state during the photoabsorption process. The best agreement between theory and experiment is obtained by considering a relative weight of 68% and 32% for the two absorption channels $3{d}^{10}L$ and $3{d}^{9}$, respectively.