Haeccety or Haecceity: How To spell?

The word Haeccety is misspelled against Haecceity, a noun meaning "Literally, this-ness. A scholastic term to express individuality or singleness; as, this book."

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