Aggressive fish

HI all,

I have a big green terror, a big oscar, a big pl*co, and a convict cichlid.
They were in a 40 gallon tank and were all getting along just fine for more
than 3 years. The day before yesterday, I moved them into a 100 gallon
tank. Ever since the move, the green terror will not let the little convict
come out of his hiding place. He chases him around the tank relentlessly.
The poor little guy has not even been able to eat. Is there anything I can
do? I don't want him to have to live in the little hiding rock forever and
he needs to eat. Thanks. Sarah