Meaning of the Header Line for Space Groups

Here's the first line in the description of this space group.

The lattice type is monoclinic, the point group of the lattice is 2/m, the full symbol for the space group is , and this space group is the 14th in the listing. We've covered most of this stuff except for the full symbol. The capital letter tells you what kind of lattice you're dealing with. P indicates it's a primitive lattice, while letters such as C, I, or F indicate types of centered cells. Some of the symmetry elements in this space group are a screw axis with a c glide perpendicular to it. The screw axis is oriented along the b axis, so the symbol appears in the second position after the lattice designator.

The symbols over on the right are the space group name.

The upper symbol is the name in the Hermann-Mauguin nomenclature and is the one usually used by crystallographers. The second is a Schoenflies designator and is slightly less descriptive. This turns out to be the 5th space group with point symmetry in a systematic listing of the space groups.

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copyright © Ron Stenkamp stenkamp@u.washington.edu Most recent update 1/17/97