Heathen vs atheistical

Heathen

adj

  • Pertaining or adhering to the Germanic neo-pagan faith Heathenry. 

noun

  • An adherent of the Germanic neo-pagan faith of Heathenry. 

atheistical

adj

  • Of or relating to atheism; atheistic. 

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