In simple metals there is an important relationship between the longitudinal relaxation times T 1 and the Knight shift K, namely the Korringa relation, which states that the quantity T T 1 K 2 is constant as function of temperature T . The obtained T T 1 K 2 values against temperature are given in Fig4(a), which demonstrates that NMR parameters of 2 H in BTOD CA indeed follow the Korringa relation. Moreover, the magnetic susceptibility was determined as a function of temperature (see Fig. )), which is essentially constant in this temperature range (varies less than 10% from the mean value). This is in agreement with the character of the material as the Pauli susceptibility is temperature independent, while for the polaronic state the susceptibility is expected to change by several orders of magnitude over this tem-perature range according to a Curie-Weiss law. Together these observations provide unambiguous evidence for metallic character in the electronic structure of the studied materials. Moreover, the data indicate that the bandstate electronic structure is prevalent for different hydride contents y = 0.13 0.31 and within the temperature range of ⇠ 100 300 K. However, our conclusions are in discrepancy with the study by Bouilly et al. , who investigated the electric conductivity of epitaxial films of barium titanium and reported semiconducting behaviour at low hydride concentrations y < 0.2, while metallic character was detected with y > 0.2. Furthermore, with moderate hydride content a semiconductor-metal transition at ⇠ 200 K was observed. Previously, it was proposed that strain in epitaxial films could favor polaron formation, which would account for the discrepancies with the current study.