Crystal chemistry of borates: the classification and algebraic description by topological type of fundamental building blocks.

The structural characteristics of all the borates available were analyzed using the Inorganic Crystal Structure Database. The fundamental building blocks (FBBs) in 841 borates were systematically classified into 6 types in terms of their topological structures. By including the polymerization of the FBBs in the borate structure, a novel systematic classification and an algebraic description of borates have been proposed. The current systematic borate classification, in which all the identical FBBs can be classified into the same type, is more reasonable and provides new insight into the structural differences between various borates. The current, simpler, algebraic description is more extensive and can reflect more of the structural information of borates. This thus provides an impetus for elucidating the topological features of borates. Our work also provides much useful information on the design and search for novel borates, which is also helpful to classify newly synthesized borates and to strengthen the understanding of the overall scope of borate structures.