Figure 2.13. Calcite (CaCO3) Structure in Motion. These two animations show calculated atom movements in calcite at 300 K and at 1200 K. In the images Ca is blue, C is gray, and O is red. Each animation has its own video control, which you should click to start the animation. The time is not specified but but each second of the animation is on the order of a femosecond of motion, with the 1200 K animation slowed down more than the 300 K animation. These models of thermal vibration help us appreciate the character of atom movements in crystals and the change in magnitude in response to a change in temperature. The animations were created by Martin Dove's research group and were downloaded from their Cambridge website in 2008 (no longer online), and shown here with Martin Dove's permission.