Rhean or Rhein: How To spell?

The word Rhean is misspelled against Rhein, a noun meaning "Chrysophanic acid."

Word contains consecutive vowels 'EI' in between alphabets rh & n is misspelled as 'EA'
Wrong Spelling:  rh-ea-n 
Correct Spelling:  rh-ei-n 
Explore spell check of Rhein to spell without errors.