[en] Electron-vibrational luminescence and laser excitation spectra of Eu³⁺ in anhydrous formates Ln_0.95Eu_0.05 (HCOO)₃(Ln=La, Eu, Y) and crystallohydrates of two structural types: Ln_0.95Eu_0.05 (HCOO)₃x2H₂O (Ln=Yb, Lu) and Y_0.95Eu_0.05 (HCOO)₃x2H₂O, have been studied. Each of the three types of formates is characterized by individual electron-vibrational spectrum, in which structural peculiarities of the compounds are reflected: symmetry of Ln³⁺ ion immediate surrounding, the presence of additional ligands (water molecules), the way of formate group coordination, bond strength. Deuteration by formate ion and water permitted to identify electron-vibrational bands related to external and internal vibrations of ligands. Translational and librational vibrations of coordination-bound water molecules are considered