Recently a new crystalline phase of aluminium tris(8-hydroxyquinofnate) (Alq(3)) called delta-phase has been reported. On the basis of luminescence data, the presence of the facial isomer has been suggested. Using time dependent density functional theory calculations we compared the spectral features of meridianal and facial Alq(3). Comparisons between the two isomers have been used to confirm the presence of facial Alq(3) in delta-phase crystals. The interpretation of some characteristics of the more studied meridianal isomer has been suggested. (C) 2002 Published by Elsevier Science B.V.