Desm or Deism: How To spell?

The word Desm is misspelled against Deism, a noun meaning "The doctrine or creed of a deist; the belief or system of those who acknowledge the existence of one God, but deny revelation."

Word contains consecutive vowels 'EI' in between alphabets d & sm is misspelled as 'E' as letter 'I' is phonetically ignored
Wrong Spelling:  d-e-sm 
Correct Spelling:  d-ei-sm 
Explore spell check of Deism to spell without errors.