The Se-Sb-Se bond angles distribution also shows similar characteristics for all samples, as with the increase of Sb concentration a shift down to the 111[+ or -]5[degrees] can be observed implying considerable distortion in [Sb.sub.3] planar geometry.
In addition to that the available literature survey stimulated our interest to obtain structural information, optimized geometry of ligand HNMAMQ, and its complexes by computing the minimum satiric energy and the theoretical physical parameters, such as bond length and bond angles using MM2CS Chem 3D Ultra 11.0 version molecular modeling program; these models are necessary to obtain a constant, more precise picture of the biological active molecule at the atomic level and furthermore provide new insights that can be used to design novel therapeutic agents.
To estimate the uncertainty grade in the atomic positions from the selected glutamate structures, we measured the following internal variables for the heavy atoms: (a) bonds length; (b) bond angles; and (c) dihedral angles.
For simplicity, the confirmation of this model was assumed to have a fully extended planar zigzag structure (20) with the liber identity period of 4.1 nm that can be calculated from bond length and bond angle for each component.
The result is a distorted tetrahedral arrangement in which the H--O--H angle is 104.5[degrees], instead of a tetrahedral geometrical structure in which the bond angle of H--O--H would have been 109.5[degrees].