[formula omitted] and [formula omitted] astrophysical S factors from the no-core shell model with continuum.

The 3 He( α , γ ) 7 Be and 3 H( α , γ ) 7 Li astrophysical S factors are calculated within the no-core shell model with continuum using a renormalized chiral nucleon–nucleon interaction. The 3 He( α , γ ) 7 Be astrophysical S factors agree reasonably well with the experimental data while the 3 H( α , γ ) 7 Li ones are overestimated. The seven-nucleon bound and resonance states and the α + 3 He/ 3 H elastic scattering are also studied and compared with experiment. The low-lying resonance properties are rather well reproduced by our approach. At low energies, the s -wave phase shift, which is non-resonant, is overestimated. [ABSTRACT FROM AUTHOR]