The carbon bonds in a benzene molecule oscillate between single and double bonds. As they do so, the distances between the carbon atoms changes (as the attached animated GIF illustrates). 
At absolute zero all molecular motion ceases; that is, the molecules stop bouncing into each other, but does that mean that molecules like benzene also cease their internal molecular motion?
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$\begingroup$ chemistry.stackexchange.com/questions/51626/… chemistry.stackexchange.com/questions/50005/… chemistry.stackexchange.com/questions/31352/… $\endgroup$– MithoronCommented Jun 19, 2018 at 20:59
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2$\begingroup$ They don't oscillate like that even at room temperature. Instead, they kinda stay halfway between. The picture does not illustrate what you think it does. $\endgroup$– Ivan NeretinCommented Jun 19, 2018 at 21:26
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3$\begingroup$ The distances between the carbon atoms certainly change, but the bonds do not oscillate between single and double bonds... $\endgroup$– orthocresolCommented Jun 19, 2018 at 21:41
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$\begingroup$ This is not a duplicate, because the question conflates resonance structures with molecular motion and vibration. $\endgroup$– pentavalentcarbonCommented Jun 19, 2018 at 22:57
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"At absolute zero all molecular motion ceases; that is, the molecules stop bouncing into each other"
This statement is a common misconception about absolute zero and is totally false. At absolute zero, we are simply in the lowest possible energy state. That does not mean that molecular motion ceases. That would violate the uncertainty principle.
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1$\begingroup$ To be more specific, molecules still have zero-point (vibrational) energy at absolute zero. One should not confuse molecular (nuclear) motion with electronic motion, which is even less well-defined due to electron positions being probability distributions. $\endgroup$ Commented Jun 19, 2018 at 22:56
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$\begingroup$ When I said, "...all molecular motion ceases," I tried to qualify that by adding, "...molecules stop bouncing into each other." If the last statement is false, some clarification would be appreciated. If there is a term for motion within an atom and motion as one atom relates to a neighboring atom, I am not aware of it or have forgotten it. $\endgroup$– BillDOeCommented Jun 19, 2018 at 23:24
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1$\begingroup$ @BillDOe He (at 1atm) is not even a solid in the limit of absolute zero. physics.stackexchange.com/questions/274910/… It remains liquid, so the atoms are certainly bouncing into each other. $\endgroup$ Commented Jun 20, 2018 at 3:13
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$\begingroup$ Thanks. I'm obviously a victim of that common misconception. $\endgroup$– BillDOeCommented Jun 20, 2018 at 18:04