use bitmasks
BEGIN_SHELL [ /usr/bin/env python3 ]
from generate_h_apply import *
from perturbation import perturbations

s = H_apply("mp2")
s.set_perturbation("Moller_plesset")
#s.set_perturbation("epstein_nesbet")
print(s)

s = H_apply("mp2_selection")
s.set_selection_pt2("Moller_Plesset")
print(s)
END_SHELL