FINITE-ELEMENT MULTICONFIGURATION HARTREE-FOCK CALCULATIONS OF THE ATOMIC QUADRUPOLE-MOMENTS OF EXCITED-STATES OF BERYLLIUM, AL, INDIUM, NE, AR, KR, AND XE

The atomic quadrupole moments Q(zz) of Be(2S2P;P-3(2)), Al(3p;P-2(3/2)), In(5p; P-2(3/2)), Ne(2p(5)3sP-3(2)), Ar(3p(5)4s;P-3(2)), Kr(4p(5)5S;P-3(2)), and Xe(5p(5)6s;P-3(2)) have been calculated using a finite-element multiconfiguration Hartree-Fock method. The obtained Q(zz)(Be) of 2.265 a.u. agrees with previously calculated values. The calculated Q(zz)(Al) and Q(zz)(In) of 2.579 and 3.165 a.u. are in good agreement with the experimental values of 2.53(15) a.u. and 2.94(10) a.u. A large s-d polarization contribution to the Q(zz) of the rare gases is found in the present calculations. The correlation contributions from double (D), triple (T), and quadruple (Q) excitations to the Q(zz) of the rare gases alternate; the total DTQ correlation contribution is negligibly small for Ne, Ar, and Kr, while the DTQ correlation contribution to the Q(zz)(Xe) is 25% of the final Q(zz). The final values are Q(zz)(Ne)=-0.0506 a.u., Q(zz)(Ar)=-0.0553 a.u., Q(zz)(Kr)=+0.0601 a.u., and Q(zz)(Xe)=+0.4505 a.u., as compared to the experimental values of -0.048(5) a.u., -0.042(4) a.u., +0.046(5) a.u., and +0.30(3) a.u. for Ne, Ar, Kr, and Xe, respectively.