Simulations of X-ray absorption spectra: the effect of the solvent

Abstract

We perform quantum mechanics/molecular mechanics molecular dynamics simulations on the [Pt₂(P₂O₅H₂)₄]⁴⁻ (abbreviated PtPOP) complex; in water, dimethylformamide and ethanol. These are used to calculate the ground state X-ray absorption spectrum of the complex. The structural parameters from X-ray spectra are usually extracted using a fit of the experimental data. In such simulations the solvent is neglected meaning that any effect of the local environment will be compensated for by structural changes of the solute, leading to possible discrepancies in the extracted structural parameters. Our simulations show a significant solvent effect on the spectra, which has important implications for the structural analysis of molecules in solution.