@Mithoron Ok :). But in my book (Solomons) it is given superimposable is different concept and superposable is the more appropriate one for chirality check. That's why I made the edit to the post. Even IUPAC's gold book - see this - uses the term superposable in place of superimposable. The latter term is just imposing the compounds, but the former means imposing and comparing the arrangement of atoms around the chirality centre.
@Loong Understood. Sorry for that, I referred the gold book. I didn't know there is variation in the spelling of centre.
@Loong, Could you please tell whether the edit for superimposability is valid. I am not going to edit again but I wish to know the correct concept at least. I edited that on the lines of the book - Solomons, Fryhle, Snyder.
I just tried to make the answer in accordance to IUPAC's guidelines.
@Intellex I don't see how you've arrived at different definitions of 'superposable' and 'superimposable'. True, the IUPAC publications only use 'superposable', but I cannot find any source in which it defines 'superimposable' in a different manner or specifies that it is an incorrect term.
In practice, both are used interchangeably. For what it's worth, your message is the first time I've seen somebody try to differentiate the two terms.
I was preparing $\ce{Mn3O4}$ but it was when characterized by XRD, a $\ce{Mn2O3}$ phase existed. Now how can I convert $\ce{Mn2O3}$ to $\ce{Mn3O4}$?
The Periodic Table
The Periodic Table