principle of least nuclear motion

https://doi.org/10.1351/goldbook.P04849
The hypothesis that, for given reactants, the reactions involving the smallest change in nuclear positions will have the lowest @A00102@. (It is also often simply referred to as principle of least motion.)
Source:
PAC, 1994, 66, 1077. (Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994)) on page 1134 [Terms] [Paper]