IPA: /ˌaɪsəˈmɔrfəs/
KK: /aɪˈsɒmərfəs/
Relating to or having the same form or structure as something else.
The two crystals are isomorphous, meaning they have the same arrangement of atoms.
Isomorphous → It is formed from "iso-" (from Greek "isos", meaning equal) and "morphē" (meaning form or shape) and "-ous" (meaning possessing or full of). The word describes substances that have the same form or structure.
Think of 'equal' ('iso-') shapes or forms ('morphē') — that's why isomorphous refers to things that have the same form.