Zeolites and related microporous solids are three-dimensional four-connected nets
where knots are tetrahedral atoms (Si,Al,P,Ge,...). A surprise comes when by only
considering a few combination rules, more than 140 different materials have been
characterised to this date, and hypotethical structures (that could be synthesised)
are virtually countless. A part of the secret of this amazing variety comes from
the flexibility of T-O-T angles, and so different topologies can -by deforming
from equilibrium of dense structural binding shown by quartz and others- can
be accommodated with reasonable strain that does not break the structure. In fact
all the microporous structures are quite stable. Characterisation of new structures
comes from two points: topology and bond angles and distances. An automated
way of calculating all these many data from the unit cell was lacking and a fortran
code for this purpose has been developed by our group (in collaboration with
Julian Gale). 'zeoTsites', as our code is called calculates all the necessary
data and shows the results in an orderly and elegant format so that the special
features of each structure are catched at a glimpse. More on this can be seen in this
web page (
zeoTsites: a software tool for zeolites).