We present a comprehensive study of the growth of GaN(1 (1) over bar 00) on gamma-LiAlO2(100) by plasma-assisted molecular beam epitaxy. Pure GaN(1 (1) over bar 00) layers are obtained preferentially on a particular face of the substrate. We provide a means by which to identify this face by simple chemical treatment. Nitridation of the substrate prior to growth as well as immediate N-rich nucleation conditions invariably induce phase mixture. In contrast, immediate Ga-rich nucleation is found to result in the growth of pure GaN(1 (1) over bar 00) films. Layers nucleated at low temperature exhibit the highest structural and morphological quality reported so far for non-[0001]-oriented structures. (C) 2003 American Vacuum Society.