Hi Karsten:
The wiki is an excellent beginning.
May I suggest "MoI" with capital "I", and "MoI's" for possessive form.
Humor: As a native English speaker, with slightly imperfect grammer after all these years of experience and school, I looked up "geometric,"
and "geometrical." "Geometrical" seems to be a wee bit more general. Your use looks perfectly acceptable to me.
http://english.stackexchange.com/questions/171509/geometric-or-geometrical

- Brian