Rheen or Rhein: How To spell?

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

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