Five types of radicals were considered in order to describe the experimental EPR spectra of polycrystalline calcium gluconate irradiated with gamma quanta. This set made it possible to correctly describe the X- and Q-band EPR spectra of CaGluc2·H2O with one set of anisotropic parameters HFI and g-factors. Because it is assumed that irradiation with gamma quanta leads to the rupture of the C-H bond; hydrogen atoms in the structure of the calcium gluconate molecule, bound directly to the carbon atom, were successively removed. Tensors of anisotropic HFIs and g-factors were calculated by the density functional theory (DFT) (unrestricted Kohn-Shem method). Meta-GGA functional (TPSS) and ccpVDZ basis were used. In this case, the EPR spectra parameters calculated in the ORCA program and determined by fitting in the EasySpin program differ insignificantly. The torsion angles obtained from the EPR data are consistent with the X-ray diffraction data [10]. This indicates the possibility of using this method for the conformational analysis of the studied compounds.

为了描述用伽马量子辐照的多晶葡萄糖酸钙的实验 EPR 光谱，考虑了五种类型的自由基。这组可以使用一组各向异性参数 HFI 和 g 因子正确描述 CaGluc2·H2O 的 X 和 Q 带 EPR 光谱。因为假设伽马量子辐照会导致 CH 键断裂；葡萄糖酸钙分子结构中直接与碳原子结合的氢原子被相继去除。各向异性 HFI 和 g 因子的张量通过密度泛函理论 (DFT)（不受限制的 Kohn-Shem 方法）计算。使用了 Meta-GGA 泛函 (TPSS) 和 ccpVDZ 基础。在这种情况下，在 ORCA 程序中计算的 EPR 光谱参数与通过 EasySpin 程序中的拟合确定的差异不大。从 EPR 数据获得的扭转角与 X 射线衍射数据一致 [10]。这表明使用该方法进行研究化合物的构象分析的可能性。