Structure of Zinc Blende, with each S2- surrounded by four Zn2+.
Tetrahedral coordination polyhedra are shown in Solid and Wired styles,
with autonomy All and None, to ilustrate the new Polytope functionality.
The Layer is represented with white background, often the best option
when preparing a picture for publication. Gnome on Fedora 8.
Size: 51,963 bytes.
Coordination polyhedron obtained from 50,000 atoms randomly distributed
inside a cube. This is exactly the same code used to obtain small
coordination polyhedra as above for Zinc Blenda. Technically this
is an implementation of a 3D convex hull incremental algorithm,
with conflict lists to achieve NlogN scaling. It takes just 3-5
seconds to complete, because most atoms are deep inside the
cube and can be efficiently discarded. Gnome on Ubuntu 9.04.
Size: 32,761 bytes.
Coordination polyhedron obtained from 50,000 atoms (almost) randomly
distributed on the surface of a sphere. This case takes much more
time to calculate (about 30 seconds) because all atoms contribute
to the final polygonal surface. As atoms are added one at a time (3D
convex hull incremental algorithm), the polygonal surface must be
locally recalculated 50,000 times. Gnome on Ubuntu 9.04. Size: 41,309 bytes.
A 3x3x2 convencional cell volume of orthorhombic (group 47)
YBa2Cu3O7
superconductor, shown here with 2D squares and 3D square piramids to emphasize
the oxygen coordination around copper. Outer atoms were removed to improve
readability. Wyckoff coordinates were taken from Ira Burshtein
Crystal Structures
site. Gnome on Fedora 8. Size: 35,354 bytes.
Screenshots for older releases can be found here.