Molecular Configuration Around Single Vacancy in Solid CO2 at T = 0 K Studied by Monte Carlo Simulation Technique

Energetically minimum configurations of the first- and second-nearest neighbor (NN) CO2 molecules surrounding a vacancy, created by removing a single molecule from the Pa3 structure, were calculated by use of the Monte Carlo simulation technique at zero temperature. It was found that among the 1st NN molecules, only six NN molecules, closest to the oxygen atoms of the removed CO2 molecule, significantly changed the positions and orientations, while the other six molecules were not influenced by the creation of the vacancy. The configurations of the molecules no longer had the three-fold symmetry that the Pa3 structure possessed. The influence of the vacancy on the 2nd NN molecules was relatively small.