I was wondering how a molecule transforms from one conformation into another. Surely, since the conformations are separated by a potential barrier, some activation energy must be required. The energies related to a molecule are translational, rotational, vibrational, and electronic. Out of these, translational and rotational motion do not change the intrinsic coordinates of a molecule, and these won't bring about a conformational change. The electronic transitions are too fast on the conformational time scale. This leaves, at least for an independent molecule, vibration as the only candidate for bringing about conformational transformations. Although collisions may also be considered, my focus is on independent molecules. I tried searching for a relation between conformations and vibrations but couldn't find any relevant results.
Yes, you can think of conformations as arising from vibrational modes, typically low-energy ones. In fact, some conformational search methods use low-energy dynamics or projection to find new conformers.
I think Paul Hawkins still has the best review: "Conformation Generation: The State of the Art" (2017)
Stochastic methods based on Monte Carlo-simulated annealing (23) (MC) are often faster than MD methods. (24, 25) Methods based on low-mode or normal-mode searching attempt to retain the sound physics of MD while requiring still less computation time. (26-29) However, all these methods can still require many CPU minutes to produce conformations for a single molecule and are therefore unsuitable for processing even a few thousand molecules. Additionally, for MD and MC approaches (but, to a lesser degree, low-mode MD methods), the input conformation, which is required in all these methods, can bias the sampling, requiring the use of either multiple input conformations or longer sampling time.
Thus, many conformer search techniques either drive torsional angles or use distance-geometry (e.g. RDKit / ETKDG) as ways to stochastically project new conformer minima without needing MD or biasing the search.