This applet models the symmetry operations of the octahedral group Oh. Click on the C1 box to see the animation for the operation, a 360 degree rotation (which is equivalent to the identity operation).
There is one C2, a 2-fold (180 degree) rotation, and a C4, a 90 degree rotation.
The C3 rotation is often difficult to see, particularly if one looks only down the Cartesian axes. That is why an "oblique view" is provided to show the 3-fold rotation axis, which revolves about the line x=z (the set of all points (x, 0, x) in R3.
The letter σ represents a mirror plane, which reflects one part of the molecular into the other half. σh is the horizontal mirror plane, in the plane of the screen - it reflects the top half of each atom into its bottom half. σv is the vertical mirror plane, perpendicular to the plane of the computer screen. It reflects the right half of the pentagon into the left, reflecting the right half of atom 1 into the left half of 1. Yellow color is used to suggest a reflective glass.
A classic example of this group is the compound SF6.
© 2003-2011 by Lawrence T. Sein. All rights reserved.
Send questions to: lseinjr@hotmail.com