Effective Interactions in ${\mathrm{C}}^{14}$

Conventional shell-model calculations on the assumption of $\mathrm{jj}$ coupling have been made for the level spectrum of ${\mathrm{C}}^{14}$ considering ${\mathrm{C}}^{12}$ as the core. The three different choices of the exchange mixture considered are (a) $s$-state interaction only, (b) singlet-even interaction only, and (c) singlet-even and triplet-odd interaction. The configuration-mixing effects are also studied and are found to be insignificant. The energy levels are satisfactorily explained with an attractive but weak singlet-even (Serber-type) interaction operating only in $s$ and $d$ states, and of a fairly long Gaussian range. The importance of the $d$-state forces is pointed out and the configuration assignments to various levels are made.