A displacive crystal distortion to lower symmetry that cooperatively removes a localized-electron
orbital
degeneracy at an array of like atoms so as to leave the atoms in the centre of symmetry of their
distorted sites. Example: The crystallographic distortion in
Mn3O4.
Source:
PAC, 1994, 66, 577
(Definitions of terms relating to phase transitions of the solid state (IUPAC Recommendations
1994))
on page 584