isosteric

[ ahy-suh-ster-ik ]
/ ˌaɪ səˈstɛr ɪk /

adjective

Chemistry. having the same number of valence electrons in the same configuration but differing in the kinds and numbers of atoms.
Meteorology. having or showing equal atmospheric density.

Origin of isosteric

1860–65; iso- + Greek ster(eós) solid, hard + -ic

British Dictionary definitions for isosteric

isosteric
/ (ˌaɪsəʊˈstɛrɪk) /

adjective

(of two different molecules) having the same number of atoms and the same number and configuration of valency electrons, as carbon dioxide and nitrous oxide