Several stable structures of 1:1:1 anion-lithium ion-ethylene glycol (EG) complexes have been obtained by ab initio calculations at the Hartree-Fock level of theory (HF/6-31G*). The anions investigated are BF4-, ClO4-, PF6-, AsF6-, CF3SO3-(Tf-), and [(CF3SO2)(2)N](-) (TFSI). Larger basis sets and electron correlation effects have been accounted for by performing single-point calculations (HF/6-311+G*//HF/6-31G* and MP2/6-311+G*//HF/6-31G*). The advantages of the 1:1:1 complexes as model systems for ion pairing in polymer electrolytes are outlined with emphasis on. the coordination geometries and the resulting vibrational spectra. Comparisons are made with calculated data for "free" anions and 1:1 lithium ion-anion ion pairs and experimental spectroscopic data. On average, the 1:1:1 complexes reproduce the experimentally observed vibrational shifts better than the 1:1 ion pairs. The results are discussed in relation to the usually encountered nomenclature; solvent-separated ion pairs, solvent-shared ion pairs, and contact ion pairs.