Team good enough to solo Gengar?

Very safe for focus blast, but you need dodging skills for shadow ball and sludge bomb

Put Tyranitar last as it has less DPS than Espeon/Alakazam and its main job is to tank. 3-bar Crunch is also excellent for finishing the raid.

LIke Lecafe88 said, you need to dodge. Generally speaking, Gengar raids are mainly failed because of fainting out, not because of timing out, so prioritize dodging. FB and ShB are easy to dodge, SlB is a bit harder.
Gengar with Shadow Ball is also one of the best counters, especially if the boss has Focus Blast.

I think its a great team although if you have a CTM, Id use it on that second Espeon. Either FS or Psybeam is better than Psychic

If for some reason it doesn't work, Groudon with MS/E works wonders on Gengar (if you have one at lvl 30).