Presupernova evolution and explosive nucleosynthesis of zero metal massive stars

We present a new set of zero metallicity models in the range 13-80 $\rm M_\odot$ together to the associated explosive nucleosynthesis. These models are fully homogeneous with the solar metallicity set we published in Limongi & Chieffi (2006) and will be freely available at the web site http://www.iasf-roma.inaf.it./orfeo/public{_}html. A comparison between these yields and an average star that represents the average behavior of most of the very metal poor stars in the range $-5.0<[\mathrm{F}\mathrm{e}\mathrm{/}\mathrm{H}]<-2.5$ confirms previous findings that only a fraction of the elemental [X/Fe] may be fitted by the ejecta of $standard$ core collapse supernovae.