Carbon dioxide–water clusters in the atmosphere of Mars

The possibility of carbon dioxide–water binary nucleation in the atmosphere of Mars has been raised by some recent studies. We have studied the possible formation of mixed water–carbon dioxide clusters under Martian conditions using quantum mechanical calculations. We have performed these calculations for two different conditions relevant to the Martian atmosphere; high temperature and high water concentration, and low temperature and medium to low water concentration. In agreement with most observations, our results point to the formation of pure water clusters when the temperature and water concentration are high, and to the formation for pure carbon dioxide clusters when the temperature and water concentration are low. In the case of low temperature and medium water concentration, the stability of water clusters containing one carbon dioxide molecule is near the stability of pure clusters, so we cannot rule out the formation of these clusters in the Martian atmosphere under such specific conditions.