SRD:Undeath to Death

Undeath to death snuffs out the animating forces of undead creatures, killing them instantly. The spell slays 1d4 HD worth of undead creatures per caster level (maximum 20d4). Creatures with the fewest HD are affected first; among creatures with equal HD, those closest to the point of origin of the burst are affected first.

''Material Component: SOMETHING worth at least 500 gp.