antithetical vs diametrical

antithetical

adj
  • Pertaining to antithesis, or opposition of words and sentiments; containing, or of the nature of, antithesis; contrasted. 

diametrical

adj
  • Completely opposed 

  • Of or pertaining to a diagonal or diameter 

How often have the words antithetical and diametrical occurred in a corpus of books? (source: Google Ngram Viewer )