    &FORCEFIELD
      ZBL_SCATTERING
      &CHARGE
        ATOM U
        CHARGE 4.0
      &END
      &CHARGE
        ATOM O
        CHARGE -2.0
      &END
      &SHELL U
        CORE_CHARGE   -2.840000
        SHELL_CHARGE 6.840000
        MASS_FRACTION  0.01
        SPRING  [eV*angstrom^-2] 171.556
        MAX_DISTANCE [angstrom] 0.1
      &END SHELL
      &SHELL O
        CORE_CHARGE 1.186267
        SHELL_CHARGE -3.186267
        MASS_FRACTION 0.1
        SPRING [eV*angstrom^-2] 70.824
        MAX_DISTANCE [angstrom] 0.05
      &END SHELL
      &NONBONDED
        &WILLIAMS
          atoms U  O
          A [eV] 844.41
          B [angstrom^-1] 2.35159661652
          C [eV*angstrom^6] 0.0
          RCUT 10.4
        &END WILLIAMS
        &BUCK4RANGES
          atoms O O
          A [eV] 20908.03
          B [angstrom^-1] 7.71604938272
          C [eV*angstrom^6] 229.04
          R1 1.17
          R2 1.62
          R3 2.84
          POLY1 [eV] 4204.472427467161  -7959.112702279119   6021.074988330987  -2270.766871550818 426.319753380798 -31.850801875744
          POLY2 [eV] 6.734634669569  -6.692698089020 1.656245757939  -0.122636741736
          RCUT 10.4
        &END BUCK4RANGES
        &WILLIAMS
          atoms U U
          A [eV] 0.0
          B [angstrom^-1] 0.0
          C [eV*angstrom^6] 0.0
          RCUT 10.4
        &END WILLIAMS
      &END NONBONDED
      &SPLINE
        R0_NB   0.05
        EMAX_SPLINE 100
      &END
    &END FORCEFIELD
