MD simulations and DFT calculations have been extensively used to study ACC and carbonate compounds to understand their structures and phase stability. Well-validated force field parameters for MD simulations have reproduced the thermodynamic properties and structures of carbonated materials, including ACC. DFT calculations employing reliable electron correlation functions have also predicted the stability of various vaterite structures. The phase transition from ACC to vaterite crystals requires overcoming an energy barrier of approximately 5 to 20 kJ/mol. Unfortunately, equilibrium MD simulations cannot overcome this energy barrier within an accessible timescale. Additionally, the relative energy differences among vaterite polymorphs, as determined by DFT, are typically only a few kJ/mol. This low rotational barrier of CO 3 2in the interlayer complicates the prediction of phase transitions among vaterite polytypes using MD.