isomerization vs isomerisation

isomerization and isomerisation both are nouns.

Word	Noun	Adjective	Verb	Adverb
isomerization	Yes	No	No	No
isomerisation	Yes	No	No	No

As nouns, isomerization and isomerisation are synonyms defined as:

isomerization and isomerisation: the conversion of a compound into an isomer of itself

isomerization (noun)	isomerisation (noun)
the conversion of a compound into an isomer of itself	the conversion of a compound into an isomer of itself