Upma and Mohan L. Verma
Biopolymer Chitosan has physico-chemical properties that open up a wide span of applications in many sectors. In this paper we report a theoretical study of Chitosan. This is an ab initio study based on density functional theory implemented in computational program SIESTA with use of LDA and GGA scheme for an account of exchange corelation effect to obtain density of states(DOS), projected density of states(PDOS), charge density, Mulliken, Hirshfeld, Voronoi population and crystal orbital overlap populations COOP analysis of Chitosan. In the first step structure of Chitosan is optimized for lowest energy value for LDA and GGA. On the basis of band plots and PDOS, it can be stated that for LDA the system under study is electronically semiconductor and for GGA it is insulator. The charge density analysis proves it as ionic conductors. The contributions to the top of valence band (HOMO) and bottom of conduction band (LUMO) come predominantly from O s/p, N s/p , C s/p and H s states, respectively. This is the first principles study to observe theoretically the effect of Chitosan before its further application as an electrolyte in various electro-chemical devices
