[gethingriffith]

Alright guys, got an exam tomorrow so i need to brush up on some stuff. This is the question:
SrFeO3 is a metal. Account for this difference in behaviour from LaFeO3
I understand that LaFeO3 is an insulator due to the relatively small bandwidth of the d-orbitals in the first row transition elements, so the electron-electron repulsion is greater than the bandwidth and therefore it is a Mott insulator. For SrFeO3, does it have to be that the Sr is in oxidation state +2 and the Fe in oxidation state +4, therefore the electrons can hop from one ion to the other and by doing that avoiding the U penalty, therefore is a metal?
Regards