  The modifications in the electronic structure of Ni_{2+x}Mn_{1-x}Ga by Ni
doping have been studied using full potential linearized augmented plane wave
method and ultra-violet photoemission spectroscopy. Ni 3d related electron
states appear due to formation of Ni clusters. We show the possibility of
changing the minority-spin DOS with Ni doping, while the majority-spin DOS
remains almost unchanged. The total magnetic moment decreases with excess Ni.
The total energy calculations corroborate the experimentally reported changes
in the Curie temperature and the martensitic transition temperature with x.
