In the monoclinic system, the cell is based on the shortest possible vectors in the ac plane with b the unique axis.
In all cases then, the practice for the monoclinic system would be to select a conventional cell based on the shortest vectors in the ac plane (b-axis unique) for primitive as well as centered cells.
Carbon tetrachloride III crystallizes in the monoclinic system
In addition, to facilitate the use of these conventions, Volume A of the International Tables for Crystallography has been expanded to give explicitly the required space group settings in the monoclinic system (e.
Consequently, in Table 7, the compounds reported in the monoclinic system represent cases with potential error.
Skipping over the technical discussions of the isometric, tetragonal and monoclinic systems
, I headed straight to the "Catalogue of American Localities of Minerals," where Dana listed many of our Bay State communities and the geologic treasures they hold.