Systemic investigations on lanthanum nitride endohedral metallofullerene La3N@C-92 are carried out by a hybrid density functional theory technique combined with statistical mechanics treatment. A novel isolated-pentagon-rule (IPR) isomer with C-2 symmetry is determined as the most suitable host cage for the encapsulation of La3N with the lowest energy and predominant thermodynamic stability related to fullerene formation. Natural electron configuration analyses reveal that electron transfer between the La3N cluster and C-92 cage is mainly contributed by the 6s orbital of lanthanum atoms. The present work may supply some information reliable for synthesis and experimental characterization of large trimetallic nitride endohedral fullerenes. (C) 2011 Elsevier B.V. All rights reserved.