masstable/masstable.py
def s2n(self):
        """Return 2 neutron separation energy"""
        M_N = 8.0713171         # neutron mass excess in MeV
        f = lambda parent, daugther: -parent + daugther + 2 * M_N
        return self.derived('s2n', (0, -2), f)
def s2n(self):
        """Return 2 neutron separation energy"""
        M_N = 8.0713171         # neutron mass excess in MeV
        f = lambda parent, daugther: -parent + daugther + 2 * M_N
        return self.derived('s2n', (0, -2), f)
Return 2 neutron separation energy