Alkyl diglycolamides (DGAs) are promising extractants for the separation of trivalent actinides from nitric acid medium. Molecular dynamic simulations using AMBER force field have been performed on various alkyl derivatives diglycolamides to understand the fundamental property and conformation of DGA responsible for extraction of trivalent metal ions. Since the amidic (O1 and O2) and etheric oxygen donor atoms in DGA molecule coordinates with metal ions, the linear distance between O1-O3 atoms and the dihedral angle associated with O1-C1-C2-O2 and O2-C3-C4-O3 bonds present in DGAs were determined by MD simulations. The results obtained were correlated to the distribution ratio of americium (III). The average O1-O3 distance increased with increase of chain length and branching of alkyl group attached to amidic nitrogen atom of DGA. The extractant underwent remarkable change in conformation, prior to coordination with metal ions, to adopt a suitable conformation necessary for efficient complexation. Comparison of the results obtained from simulation and distribution ratios, our studies revealed that diglycolamides required an optimum O1-O3 distance of 4.2-5 Å and minimal reorientation of dihedral angles for efficient coordination with trivalent metal ions.