Investigation on the stability, electronic, optical and mechanical
properties of novel calcium carbonate hydrates via first-principles
Calcium carbonate (CaCO3) is an inorganic compound which is widely used
in industry, chemistry, construction, ocean acidification and
biomineralization due to its rich constituent on earth and excellent
performance, in which calcium carbonate hydrates are important systems.
In Z.Y. Zou et al’s work (Science, 2019, 363, 396–400), they found a
novel calcium carbonate hemihydrate phase, but the structure stability,
optical and mechanical properties has not been studied. In this work,
the stability, electronic, optical, and mechanical properties of novel
calcium carbonate hydrates were investigated by using the
first-principles calculations within density functional theory (DFT).
CaCO3·xH2O (x=1/2, 1 and 6) are determined dynamically stable phases by
phonon spectrum, but the Gibbs energy of reaction of CaCO3·1/2H2O is
higher than other calcium carbonate hydrates. That’s why the
CaCO3·1/2H2O is hard to synthesize in the experiments. In addition, the
optical and mechanical properties of CaCO3·xH2O (x=1/2, 1 and 6) are
expounded in detail. It shows that the CaCO3·1/2H2O has the largest bulk
modulus, shear modulus, Young’s modulus with the values 60.51, 36.56 and
91.28 GPa with respect to other two calcium carbonate hydrates
investigated in this paper. This work will provide guidance for
experiments and its applications, such as biomineralization, geology,
and industrial processes.