Thank you Bengt Nyman. You have an interesting website on gravity and atomic structure!
For me, the simplest example of antigravity is actually totally mundane.
anvil cloud via images gawker com
The water molecules, free to rotate in an e-field, align with other dipolar water molecules.
This results in a charge separation within the cloud and a very wide, half-mile e-field surrounding some clouds.
Some of them exhibit enormous power when they punch through the atmosphere.
An explanation from "Electric Weather" follows:
“Oh for shame, how these mortals put the blame upon us gods, for they say evils come from us, when it is they rather who by their own recklessness win sorrow beyond what is given…”