https://doi.org/10.1351/goldbook.08148
Two (or more) molecules with the same spin multiplicity but with different lengths for one or more bonds.
Note:
This feature arises because the potential-energy surface, which describes how the energy of the molecule depends on geometry, shows two (or more) minima that are not merely symmetry-related.
This feature arises because the potential-energy surface, which describes how the energy of the molecule depends on geometry, shows two (or more) minima that are not merely symmetry-related.