Is it permissible to give the zakat money left by a deceased father to his orphaned children? And what are the cases that allow this?

The zakat obligatory upon the deceased during their lifetime does not lapse with their death. It must be disbursed from their estate before its division. It is permissible to give zakat to orphaned heirs if they are poor, because the fundamental principle is the permissibility of giving zakat to poor parents and children.