I don't know if this is THE church, but a church in Rome that has some pretty awesome chandeliers is Santa Maria in Aracoeli. It is by Piaza Venezia and the monument to Vittorio Emanuele II. If you are at the stairs/ramp that goes up to the Capitoline museum, it is up the long flight of stairs on your left. There is a Wikipedia page on it that doesn't mention the chandeliers, but there are certainly some inside lining the nave and two arches of the apse.