Static Quadrupole Moment of the First Excited State ofSi30

The static quadrupole moment, $Q_{2^{+}}$, and $B(E2;0^{+}\to 2^{+})$ of the first excited state of ${}_{}{}^{30}{}_{}{}^{}\mathrm{Si}$ have been measured using the reorientation effect in Coulomb excitation, giving $Q_{2^{+}}=-5\mathrm{}\pm 6(+1\mathrm{}\pm 6)e·{\mathrm{fm}}^2$ and $B(E2;0^{+}\to 2^{+})=253\mathrm{}\pm 30 (261\mathrm{}\pm 30)e^2·{\mathrm{fm}}^4$ if the interference from the second excited state is constructive (destructive). The result for $Q_{2^{+}}$ indicates that Hartree- Fock calculations which ignore solutions other than those with $K=0\mathrm{}$ are inadequate, and supports shell-model calculations and band-mixed Hartree- Fock calculations.