Photochromism occurring in complex systems and triggered alternatively by two different external stimuli, such as light and an
electric current. In such a case
photochromism and '
electrochromism' are mutually regulated.
Source:
PAC, 2007, 79, 293
(Glossary of terms used in photochemistry, 3rd edition (IUPAC Recommendations 2006))
on page 327