High-accuracy calculation of energies, lifetimes, hyperfine constants, multipole polarizabilities, and blackbody radiation shift in 39K

Excitation energies of the ns, np(j), nd(j), nf(j), and ng(j) states with n <= 7 in neutral potassium are evaluated. First-, second-, third-, and all-order Coulomb energies and first- and second-order Coulomb-Breit energies are calculated. Reduced matrix elements, oscillator strengths, transition rates, and lifetimes are determined for levels up to n=9-12. Electric-dipole (4s(1/2)-np(j), n=4-26), electric-quadrupole (4s(1/2)-nd(j), n=3-26), and electric-octupole (4s(1/2)-nf(j), n=4-26) matrix elements are calculated to obtain the ground state E-1, E-2, and E-3 static polarizabilities. Scalar and tensor polarizabilities for the 4p(j) excited state in K I are also calculated. All the above-mentioned matrix elements are determined using the all-order method. We also investigate the hyperfine structure in K-39. The hyperfine A values are determined for the first low-lying levels up to n=7. The quadratic Stark effect on hyperfine structure levels of the K-39 ground state is investigated. The calculated shift for the (F=2,M=0)<->(F=1,M=0) transition is found to be -0.0746 Hz/(kV/cm)(2), in agreement with the experimental value -0.071 +/- 0.002 Hz/(kV/cm)(2). These calculations provide a theoretical benchmark for comparison with experiment and theory.