Tuning the plasmon energy of palladium-hydrogen systems by varying the hydrogen concentration

First-principles calculations are performed to obtain the dielectric function and loss spectra of bulk PdH _x. Hydrogen concentrations between x=0 and 1 are considered. The calculated spectra are dominated by a broad peak that redshifts in energy with x. The obtained bulk dielectric function is employed to compute the loss spectra of PdH _x spherical nanoparticles as a function of x. The dominant plasmon peak in the spherical nanoparticle is lowered in energy with respect to the bulk case. However, the dependence of the resonance energy on the hydrogen concentration is roughly similar to that in bulk.