Advanced spectroscopic characterization of calcium carbonate polymorphs: Ab initio dynamic approaches and experimental Raman

• Insight into the spectroscopic properties of CaCO 3 polymorphs are presented from AIMD. • A computational approach to compute the vibrational spectra of materials is presented. • Experimental and theoretical data are presented for fingerprint lattice vibrations. • Ab initio Voronoi radii are computed and presented from Bader’s analysis. • Dynamic and static ab initio results and experimental data are compared. The vibrational spectroscopic properties of crystalline anhydrous calcium carbonate polymorphs, i.e. calcite, aragonite and vaterite, are computed with state-of-the-art computational techniques. We present a refined protocol that significantly enhances the quality of spectra obtained via the autocorrelation function formalism, particularly for ionic materials. For the first time, Voronoi Radical Tessellation (VRT) is applied for the computation of electromagnetic properties of ionic systems in combination with Bader’s Quantum Theory of Atoms In Molecules (QTAIM). The use of the later allows for the determination of accurate Voronoi radii, making VRT completely ab initio . Our findings lead the way for the accurate computation of vibrational spectra in materials where anharmonicity, temperature or conformational variety have a considerable impact in the resulting spectrum. This work represents a step forward in accurately modeling and interpreting the spectroscopic behavior of ionic materials, pushing the boundaries of computational materials science.