Fig. 4: Calcium dissolution with coordination numbers to water molecules (CN (Ca-Ow)) ranging from 1 to 3.
From: Molecular insight into the initial hydration of tricalcium aluminate
a Free energy surface, b reaction coordinate and (c) corresponding snapshots of configuration evolution along the reaction pathways. In the above representations, the sates along the dissolution pathways are notated in the form of X (CN (Ca-Ot), CN (Ca-Ow)), where X indicates the state number on the free energy surface or the snapshots (e.g., the A, B, etc.), CN (Ca-Ot) and CN (Ca-Ow) represent coordination numbers of Ca to Ot and Ow, respectively in state X. “TS” denotes the transition state. The upper right corners display the states with Helmholtz free energy values (in kJ/mol) relative to state A. The saffron yellow values above the arrows represent free energy barriers (in kJ/mol), while the black values below the arrows denote the free energy differences between two adjacent states (in kJ/mol). The arrows with varied colors signify the distinct reaction pathways that align with those depicted in (b).
