Molecular structures of CS oligo-or polymer were built in a Atomistic ToolKit Quantumwise (ATK, Synopsys, USA) environment . These included monomer, 9-mer, 18-mer and 36-mer CS chains. The 9-mer chain served as the main model for the CS chain, for which both neutral and amine-protonated pyranose were considered (1/9 and 3/9 protonated groups). Pristine CS and its partially acetylated counterparts (1/9 and 2/9 acetylated mers) were also considered.