In this work, we have made an attempt to derive a novel information theoretic topological index, net-sign identity information index, I-epsilon from the molecular electronic structure, proposed by Lee et al. [S.- L. Lee, R. R. Lucchese, S.- Y. Chu, Chem. Phys. Lett., 137 ( 1987) 279] in chemical graph theory. The performance of the net-sign identity information index along with the square root of the bonding information index,root I-b and the square root of net-sign identity information index, root I-epsilon have been compared with the most widely used molecular descriptors: Wiener index (W), Randic's connectivity index (x) and Balaban's distance sum connectivity index (J) in QSPR modeling. (c) 2008 Elsevier B. V. All rights reserved.