Opening with the Abbess Hildegard Von Bingen chant that has been sampled ad infinitum is an inauspicious start for Delerium, the group that broke out in 1997 with “Silence” featuring singer Sarah McLachlan. The original Delerium team of Bill Leeb and Rhys Fuller, which parted ways for the 2001 album “Poem,” reunite for “Chimera.” But while they uncover little new ground, their formula of sophisticated electro beats and ambient moods surrounding a bevy of female singers (including Julee Cruise and Kristy Thirsk) is still potent. Leigh Nash of Sixpence None the Richer is a sultry standout in “Run for It,” as is Rachel Fuller, who lends a folk air to “Touched.” Idyllic and romantic, wafting on trip-hop grooves and gothic synthesizer arrangements, Delerium bathe their singers in glistening light and cool sweat on an album of deeply chilled torch songs.—JD