It is known that InGaN LED can emit brilliant light though similar to 10(8) cm(2) of threading dislocations exists in the active layer. Recently, the origin of defect-insensitive emission was studied [Chichibu et al., Nature Materials 5 (2006) 810] and elucidated that -In-N- zigzag atomic chains act as effective radiative recombination centers. Relationships between growth conditions and atomic arrangements in InGaN thin films were investigated by Monte Carlo simulation in the present study. Estimated density of -In-N- zigzag atomic chains in the grown films are more than 10(20) cm (3) which is large enough compared with the density of non-radiative recombination centers, i.e., <5 x 10(18)cm (3), evaluated by Chichibu et al. (C) 2008 Elsevier B.V. All rights reserved.