Enhancement of the electric dipole moment of the electron in PbO

The a(1) state of PbO can be used to measure the electric dipole moment of the electron d(e). We discuss a semiempirical model for this state, which yields an estimate of the effective electric field on the valence electrons in PbO. Our final result is a lower limit on the measurable energy shift, which is significantly larger than was anticipated earlier: 2\W-d\d(e)greater than or equal to2.4x10(25) Hz[d(e/e cm)].