EN
The electronic structure of the ternary YNi_4B compound, crystallizing in the hexagonal CeCo_4B structure (P6/ mmm space group), was studied by X-ray photoelectron spectroscopy and ab initio calculations. Core levels and the valence band were investigated. The X-ray photoelectron spectroscopy valence band is compared with that obtained from ab initio calculations. The valence band spectrum at the Fermi level exhibits the domination of the Ni(3d) states, which are hybridized with 4d states of Y and 2p states of B. The theoretical electronic specific heat coefficientγ derived from N(E_F) is about 11.33 mJ/(mol K^2) for experimental lattice parameters. The calculated bulk modulus is B_0=1.61632 Mbar.