Deformed configuration mixing shell model calculations for the energy spectra and electromagnetic properties of low-lying collective states of ${}_{}{}^{51}{}_{}{}^{}\mathrm{Cr}$, ${}_{}{}^{53}{}_{}{}^{}\mathrm{Fe}$, ${}_{}{}^{50}{}_{}{}^{}\mathrm{Ti}$, ${}_{}{}^{52}{}_{}{}^{}\mathrm{Cr}$, ${}_{}{}^{54}{}_{}{}^{}\mathrm{Fe}$, ${}_{}{}^{53}{}_{}{}^{}\mathrm{Cr}$, and ${}_{}{}^{55}{}_{}{}^{}\mathrm{Fe}$ have been performed. For each of these nuclei these calculations give rise to a highly deformed band when a neutron is promoted from the predominantly ${\left(f_{\frac{7}{2}}\right)}^n$ "spherical" ground intrinsic configuration to the unoccupied ($\mathrm{pf}$) orbits. The $K^{\pi }$ values of these excited bands are $\frac{1}{2^{-}}$, $4^{+}$, and $\frac{7}{2^{-}}$ for the nuclei having $N=27, 28, \mathrm{and} 29$, respectively. The energy spectra and electromagnetic properties of these calculated excited bands are compared with those experimentally observed. Following high-spin members of the collective bands have been predicted by the calculations: $J=\frac{11}{2}, \frac{13}{2}, \frac{15}{2}, \frac{17}{2}, \mathrm{and} \frac{19}{2}$ levels at 2.7, 3.8, 4.36, 5.94, and 6.47 MeV, respectively, in ${}_{}{}^{51}{}_{}{}^{}\mathrm{Cr}$, $J=\frac{9}{2}, \frac{11}{2}, \frac{13}{2}, \frac{15}{2}, \mathrm{and} \frac{17}{2}$ levels at 2.94, 3.67, 4.95, 6.01, and 7.47 MeV, respectively, in ${}_{}{}^{53}{}_{}{}^{}\mathrm{Fe}$, $J=\frac{15}{2}, \frac{17}{2}, \frac{19}{2}, \mathrm{and} \frac{21}{2}$ levels at 4.65, 5.77, 7.04, and 8.41 MeV, respectively, in ${}_{}{}^{53}{}_{}{}^{}\mathrm{Cr}$, and $J=\frac{15}{2}, \frac{17}{2}, \mathrm{and} \frac{19}{2}$ levels at 5.53, 6.92, and 8.33 MeV, respectively, in ${}_{}{}^{55}{}_{}{}^{}\mathrm{Fe}$. In ${}_{}{}^{50}{}_{}{}^{}\mathrm{Ti}$, ${}_{}{}^{52}{}_{}{}^{}\mathrm{Cr}$, and ${}_{}{}^{54}{}_{}{}^{}\mathrm{Fe}$ the present model suggests an interesting possibility of $K=3^{+}$ collective band lying close in energy to the recently observed $K=4^{+}$ collective bands.

NUCLEAR STRUCTURE ${}_{}{}^{50}{}_{}{}^{}\mathrm{Ti}$, ${}_{}{}^{51,52,53}{}_{}{}^{}\mathrm{Cr}$, and ${}_{}{}^{53,54,55}{}_{}{}^{}\mathrm{Fe}$. Calculated spectra, $B\left(E2\mathrm{}\right)\mathrm{}$ and $B\left(M1\mathrm{}\right)\mathrm{}$ transition strengths, $\frac{E2\mathrm{}}{M1\mathrm{}}$ mixing ratios, branching ratios and lifetimes in deformed configuration mixing shell model formalism in ${\mathrm{}\left(\mathrm{fp}\right)\mathrm{}}^n$ model space. Modified Kuo-Brown interaction. Comparison with experiment and shell model and Nilsson model calculations.

• Received 27 March 1980

DOI:https://doi.org/10.1103/PhysRevC.22.2619