Metal hydride research

Computer programs have been developed to calculate electronic properties of transition metals and their hydrides. The programs can be used to predict such properties as crystalline stability, electronic resistivity, Fermi surfaces, bulk moduli (or compressibilities), and hydrogen coordination of the metal atoms. Such information is of fundamental importance in understanding the electronic processes which occur in transition metals and their hydrides. Detailed calculations have been performed for Li and LiH, to test the computational integrity of the programs, and of the local density exchange approximation to the Hartree--Fock exchange. Initial work on NiH has also been performed. The proton spin-lattice relaxation times T1 have been measured as a function of temperature and frequency for a sample of VH0.53. The experimental values for the T1 minimums are approximately twice as large as the minimum values calculated using the BPP model. The activation for proton diffusion in the β-phase of VH/sub x/ is estimated to be 0.21 +- 0.01 eV. Preliminary NMR studies have been performed on FeTiH1.1 (β-phase) and FeTiH1.7 (γ-phase). The nuclear relaxation times at room temperature indicate the NMR spectra are inhomogeneously broadened and proton diffusion is not rapid enough to greatly affect either T1 or T2