### Atomic Data for Lanthanum (La)

### Atomic Number = 57

### Atomic Weight = 138.9055

### Reference = E95

    Isotope    Mass        Abundance Spin Mag Moment

    138La      137.907105  0.09%     5    +3.707
    139La      138.906346  99.10%    7/2  +2.778

    La I  Ground State (1s22s22p63s23p63d104s24p64d105s25p6)5d6s2  2D3/2
          Ionization energy  44981 cm-1 (5.5769 eV)   Ref. MZH78

    La II Ground State (1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6) 5d2  3F2
          Ionization energy  89200 cm-1 (11.059 eV)   Ref. SR65