(a) Any person subject to this chapter who, with an intent to kill or inflict great bodily harm, unlawfully kills a human being in the heat of sudden passion caused by adequate provocation is guilty of voluntary manslaughter and shall be punished as a court-martial may direct.

(b) Any person subject to this chapter who, without an intent to kill or inflict great bodily harm, unlawfully kills a human being—

(1) by culpable negligence; or

(2) while perpetrating or attempting to perpetrate an offense, other than those named in clause (4) of section 918 of this title (article 118), directly affecting the person;

is guilty of involuntary manslaughter and shall be punished as a court-martial may direct.