The Collaborative International Dictionary of English v.0.48:
Schismatical \Schis*mat"ic*al\, a. Same as Schismatic. -- Schis*mat"ic*al*ly, adv. -- Schis*mat"ic*al*ness, n. [1913 Webster]WordNet (r) 3.0 (2006):
schismatical adj 1: of or relating to or involved in or characteristic of schism; "schismatic sects" [syn: schismatic, schismatical]