THE CALCULATION OF THE ELECTRON-STRUCTURE AND OPTICAL-PROPERTIES OF NITI MARTENSITE

The self-consistent calculation of NiTi B2 and B19' phases have been p erformed by tile linear muffin-tin orbital method in atomic sphere app roximation (LMTO-ASA). Two approaches for calculation of B2-phase band structure have been used and the essential differences in tile Fermi surface have been pointed out. The alterations of NiTi electron charac teristics at the martensitic transition have been analyzed. The optica l spectra and their peculiarities in B2 and monoclinic B19' phases hav e been discussed. In the frames of first principles method electron-po sitron annihilation characteristics in B2-NiTi have been investigated too. It was shown that a rather satisfactory agreement with experiment al results for NiTi was achieved.