Centrosymmetric crystal displays chiral optical responses previously believed to be impossible

Expectations over optical behaviour that have been widely held since Louis Pasteur’s seminal discoveries in 1848 have been upended by a new study. Researchers observed optical behaviours linked to chirality in crystalline lithium cobalt selenium oxide (Li₂Co₃(SeO₃)₄), a centrosymmetric crystal that as such cannot be chiral. ‘Within the inorganic crystal community there’s been a strong sentiment that you cannot have chiroptical effects under centrosymmetry,’ says Roel Tempelaar, a researcher at Northwestern University’s chemistry department who led the new work.