All calculations presented below were done by using the code HFODD [26,37], version (2.48q) or higher, which includes both the angular-momentum and isospin projections. In order to obtain converged results for isospin mixing with respect to basis truncation, in our SV calculations we used harmonic oscillator (HO) shells for nuclei, 12 shells for nuclei, and 14 shells for nuclei. In SHZ2 test calculations, we took shells for and shells for nuclei.
For the numerical integration over the Euler angles in space and isospace ( ) we used the Gauss-Tchebyschev (over and ) and Gauss-Legendre (over and ) quadratures. We took and (or 10) integration points. This choice guarantees that the calculated values of are not affected by the numerical integration error.