Ānantarika-kamma: the 5 heinous 'actions with immediate destiny' are: Killing father, killing mother, killing an Arahat, wounding a Buddha so he bleeds, creating schism in the Bhikkhu-Sangha. In A.V., 129 it is said:
There are 5 hateful and incurable humans destined to the lower world and to hell, namely: the parricide, etc. About the 5th see A. X., 35, 38. With regard to the first crime, it is said in D. 2 that if King Ajātasattu had not killed his father, he would have reached entrance into the path of Stream-entry.
Maha Thera Nyanatiloka. Manual of Buddhist Terms and Doctrines, Buddhist Publication Society, first edition 1952.