Totally ab initio prediction of the structures of CO2 molecular crystal

We have succeeded in predicting a molecular crystal structure from first principles. The potential parameters and geometry for CO2 molecule were determined by ab initio molecular orbital calculations. The experimentally observed CO2 crystal structures at low and high pressures have been reproduced by molecular dynamics method without any a priori assumptions on lattice constants nor space group symmetry. With extra pressure of 1 GPa in [010] direction, the structural change observed at about 10 GPa has also been reproduced.