keywords
- bipartite
-
In a bipartite net vertices are in two sets and vertices of each set
are only linked to those of the other set. The only nets so identified
have vertices with two different coordination numbers.
- chiral
-
This selects all structures with one of the 65 space groups with only
proper operations (operations of the first kind), viz. rotation, screw
or translation.
- clathrate
-
This term is used to refer to 4-coordinated nets based on simple
tilings by polyhedra with faces with up to 6
sides. mtn and mep are the nets of
type I and II clathrate hydrates.
- good
-
"good" structures have all shortest distances corresponding to equal
lengths and the next shortest distance > 1.4 times as large, and/or
have the order of the point symmetry at the vertices > 7.
- polar
-
This selects nets with polar symmetry (i.e. those of classes 1, 2, m,
3, 3m, 4, 4m, 6, 6m).
- regular net
-
There are 5 regular nets in which the vertices have a regular polygon
or polyhedron as vertex figure. For their natural tilings the
transitivity is 1111. Delgado-Friedrichs, O. F.; O'Keeffe, M.; Yaghi,
O. M. Acta Cryst. 2003, A59,
22-27. [transitivity pqrs means p kinds of
vertex, q kinds of edge, r kinds of tile face, s
kinds of tile]
- rod net
-
The rod nets are the nets of 2-, 3- and 4-way invariant cylinder (rod)
packings as described by Rosi et al. J. Am. Chem. Soc. 2005,
127, 1504.
- self dual net
-
A self-dual net is a net that has a tiling that is self-dual. In some
cases the self-dual tiling is not the natural one and is given in
parentheses in "tiling".
- semiregular net
-
Semiregular nets have one kind of vertex and one kind of edge (vertex
and edge transitive, or transitivity 11rs). Delgado-Friedrichs,
O. F.; O'Keeffe, M.; Yaghi, O. M. Acta Cryst. 2003,
A59, 515-525.
- simple tiling
-
In a simple tiling 2 tiles meet at a face, 3 at an edge and 4 at a
vertex. the tiles are simple polyhedra (2 faces meet at each edge and
3 at each vertex). There are nine vertex-transitive simple tilings
[choose keyword "simple tiling" and nets with one kind of
vertex]. Their duals are the nine ways of tiling space with congruent
polyhedra. See Delgado-Friedrichs, O.; Huson,
D. H. Discr. Comp. Geom. 1999, 21,
299-315. Delgado-Friedrichs, O.; O'Keeffe, M. Acta Cryst. 2005,
A61, 358-362.
- uniform net
-
In a uniform net the shortest rings contained in each angle are the
same size. See especially A. F. Wells, Three dimensional nets and
polyhedra. Wiley, New York 1977.
- uniform tiling
-
In a uniform tiling, all the vertices are the same (uninodal or vertex
transitive) and the tiles are all uniform polyhedra (vertex transitive
with regular polygonal faces). Grünbaum, B. Geombinatorics
1994, 4, 49-56. Deza, M.; Shtogrin,
M. Eur. J. Combinatorics 2000, 21,
807-814.
The correspondences with Grünbaum's numbers are:
1 | fcu |
|
11 | hex |
|
21 | hal |
2 | hcp |
|
12 | tsi |
|
22 | pcu |
3 | tcd |
|
13 | svk |
|
23 | fst |
4 | tca |
|
14 | sve |
|
24 | fee |
5 | flu-e |
|
15 | svh |
|
25 | lta |
6 | crs |
|
16 | tfs |
|
26 | bnn |
7 | reo |
|
17 | svj |
|
27 | rho |
8 | cab |
|
18 | kag |
|
28 | sod |
9 | reo-e |
|
19 | ttw |
|
10 | ubt |
|
20 | pcu-i |
- weaving
-
This selects structures with only 2-coordinated vertices (i.e.
containing threads or loops). Such structures only appear when
"weaving" is selected.
- zeolite net
-
These nets appear in the Atlas of Zeolite Structure Types
http://www.iza-structure.org/databases. Note that we always
use a maximum symmetry configuration. Generally we only include
zeolite nets with one or two kinds of vertex.
Note that zeolites have a 3-letter (upper case, bold) framework code
ABC. Generally the RCSR symbol for that net has the same letters
abc. However some zeolite codes were assigned after RCSR symbols
for the net and the letters do not match. These are with corresponding
RCSR symbol: ACO = pcb, BCT = crb,
BSV = gie, RWY = sod-a.