The first-principle technique has been employed to determine the structure of carbon dioxide (CO2) dimers, molecular chains, monolayers and the CO2/KCl(100) system. Their potential structures have been proposed. CASTEP calculation shows that CO2 molecular chains and monolayers based on two stable dimers by the electric interaction are all self-assembly system. At the coverage of 1.00 ML, two stable structures have been proposed when CO2 monolayer on the KCl(100) surface. The best one is the monolayer adsorbed on the surface with the C atom in the bridge site, the angle alpha between the molecular bond and the surface is 24 degrees. The better one is the monolayer horizontally adsorbed on the surface with the C atom in the top-Cl site. The structural parameters in the adsorption system are similar to those in the monolayer. (C) 2015 Elsevier B.V. All rights reserved.