Relativistic many-body calculations of energy levels, hyperfine constants, and transition rates for sodiumlike ions, $Z=11\mathrm{}–16$

All-order relativistic many-body calculations of removal energies are carried out for $3s$, ${3p}_{1/2},$ ${3p}_{3/2},$ ${3d}_{3/2},$ ${3d}_{5/2},$ and $4s$ states of sodium and sodiumlike ions with nuclear charges $Z$ in the range 12–16. Hyperfine constants are evaluated for each state, and reduced dipole matrix elements are determined for ${3p}_{1/2}$-$3s$, ${3p}_{3/2}$-$3s$, ${3d}_{3/2}$-${3p}_{1/2},$ ${3d}_{3/2}$-${3p}_{3/2},$ ${3d}_{5/2}$-${3p}_{3/2},$ $4s$-${3p}_{1/2},$ and $4s$-${3p}_{3/2}$ transitions. The calculations include single and double excitations of the Hartree-Fock ground state to all orders in perturbation theory. Corrections to energies are made for a dominant class of triple excitations. The Breit interaction, with all-order correlation corrections, is evaluated. Reduced-mass and mass-polarization corrections are included to third order in perturbation theory. The predicted removal energies, when corrected for the Lamb shift, agree with experiment at the 1–20-${\mathrm{cm}}^{-1}$ level of accuracy for all states considered. Theoretical fine-structure intervals agree with measurements to about 0.3% for $3p$ states and to about 3% for $3d$ states. Theoretical hyperfine constants and line strengths agree with precise measurements to better than 0.3%.