The modular approach (MA) is applied to the system composed of Ca2SiO4-, Ca(OH)2- and Ca4Si3O10-building units (BU) shortly designed by letters S, P and T (corresponding to the names of substances having the same compositions: shannonite, portlandite and triorthosilicate). Symbols n, u, [unk], ū, b, d, p, q, (n[unk]), (ūu), S, Z are used for notation of the BU's and their sequences, formulation of the stacking rules and derivation of structures satisfying the homogeneity condition. The latter form a basis for the analysis of inhomogeneous structures as series members between the homogeneous structures for which functional variations of properties and formation conditions may be constructed.
Zeitschrift für Kristallographie – Crystalline Materials offers a place for researchers to present results of their crystallographic studies. The journal includes theoretical as well as experimental research. It publishes Original Papers, Letters and Review Articles in manifold areas of crystallography.