def s1n(self):
        """Return 1 neutron separation energy"""
        M_N = 8.0713171         # neutron mass excess in MeV
        f = lambda parent, daugther: -parent + daugther + M_N
        return self.derived('s1n', (0, -1), f)
def s1n(self):
        
        M_N = 8.0713171         
        f = lambda parent, daugther: -parent + daugther + M_N
        return self.derived('s1n', (0, -1), f)
def s1n ( self ) : M_N = 8.0713171 # neutron mass excess in MeV f = lambda parent , daugther : - parent + daugther + M_N return self . derived ( 's1n' , ( 0 , - 1 ) , f )
Return 1 neutron separation energy
Return 1 neutron separation energy