The first principles density functional theory [19] has been applied to investigate the FeCl3and CrO3molecule adsorption indifferent sites of the (10,0) BN nanotubes. We used the Siesta code[20], which performed full self-consistent calculations solving the Kohn Sham equations [21]. In all the calculations we used double zeta basis set with polarization function [22]. For the exchange and the correlations terms, generalized gradient approximation with the parametrization of Perdew et al. [23] was used. The interaction between ionic cores and valence electrons is described by norm conserving pseudopotentials [24] in Kleinman–Bylander form [25].A cut-off of 250 Ry for the grid integration was used to represent the charge density. The Brillouin zone is sampled with eighteen k-points special along the _-X directions used Monkhorst–Packmethod [26].