The objective of the present study is to predict Young's modulus of polymer-layered silicate nanocomposites (PLSNs) containing fully intercalated structures. The particular contribution of this article is to consider the changes in structural parameters of different intercalated morphologies in vicinity of each other. These parameters include aspect ratio of intercalated stacks, number of silicate layers per stack, d-spacing between the layers, modulus of the gallery phase, and volume fraction of each intercalated morphology. To do this, the effective particle concept has been employed and combined with the Mori-Tanaka micromechanical model. It has been shown that the simultaneous effects of d-spacing between the silicate layers and gallery phase modulus remarkably influence the nanocomposite's modulus. Finally, the micromechanical modeling results have been compared with the experimental data and illustrates that the new approach is more accurate than the earlier model developed by the same authors. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 119: 3347-3359, 2011