Solid-state near-edge X-ray absorption fine structure spectra of glycine in various charge states

The experimental solid-state near-edge X-ray absorption fine structure spectra for a series of glycine-related samples including alpha-glycine, beta-glycine, glycinium chloride, glycinium trifluoroacetate, and sodium glycinate at the C, N, and O K-edges measured under identical conditions are reported and compared. An assignment of spectral features for alpha-glycine is proposed on the basis of extended theoretical simulations of polarization-dependent spectra performed within the real-space multiple-scattering formalism explicitly taking into account the intermolecular environment of a glycine molecule in a crystal.