The moving molecules thing doesn’t really make sense. Molecules are always moving. Is it more than a certain amount of average kinetic energy? If so temperature should matter more than state.
Molecules within a hot solid do that too. But rather than a maximum kinetic energy or temperature as JoshuaZ proposed, you can use a maximum relative displacement.
Edit: On second thought, maybe that’s already in what you said, in the word ‘significantly’. And now I notice that you wrote ‘orientation’ instead of ‘position’, so that actually changes the meaning entirely. Lesson: read carefully!
The moving molecules thing doesn’t really make sense. Molecules are always moving. Is it more than a certain amount of average kinetic energy? If so temperature should matter more than state.
Molecules constantly significantly changing their spatial orientation relative to each other.
Molecules within a hot solid do that too. But rather than a maximum kinetic energy or temperature as JoshuaZ proposed, you can use a maximum relative displacement.
Edit: On second thought, maybe that’s already in what you said, in the word ‘significantly’. And now I notice that you wrote ‘orientation’ instead of ‘position’, so that actually changes the meaning entirely. Lesson: read carefully!