collaborate vs split up

collaborate

verb
  • To work together with others to achieve a common goal. 

  • To voluntarily cooperate treasonably, as with an enemy occupation force in one's country. 

split up

verb
  • separate, disassociate, cause to come apart. 

  • Cease to be together, break apart from the group. 

adj
  • Divided or separated. 

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