Nuclear models and the osmium isotopes

The energies of, and transition probabilities involving, the ground-state rotation bands of Os186, Os188, and Os190 are compared with a diagonalized rotation-vibration theory in which vibrations are considered to three phonon order. Agreement even in the Os transition region is found to be excellent. The theory appears to be particularly successful in predicting two phonon states in Os190

Opportunity to observe an M0 transition

It seems that the best opportunity to observe a low-energy 0+ → 0- M0 transition would be in the most strongly octupole deformed nucleus 224Ac having the known 0- ground state and parity doublet bands with splittings of only ~7 keV. Based on the rigid rotor model fit to available experimental data a 0+ excited state at ~2 keV is suggested and possible mechanisms of the M0 transition to the ground state discussed

Search for the beginning of chaos in the low-energy region of well deformed even-even nuclei

A critical evaluation of all the data on the level structures of 178Hf, 168Er, 162Dy and 164Dy with special emphasis on the (n,\gamma ) studies with average resonance capture (ARC) indicates the presence of a total of 4 states which are anomalous and may be chaotic (1 in 178Hf below 1800 keV, 1 in 162Dy below 2000 keV, and 2 in 164Dy below 2000 keV) imbedded among the normal quadrupole deformed rotational states

AN ANALYSIS OF CO STRETCHING VIBRATIONS IN METAL CARBONYLS CONTAINING C13C^{13} 10.

Author Institution: Department of Chemistry, Florida State UniversityIn a recent study of the infrared absorption spectra of various metal carbonyls and their $PF_{3}$ substitution products in the CO stretching region $(1900 2100cm^{-1})$, we have been able to obtain the stretching and interaction constants for CO vibrations in these molecules. The approximation of high frequency separation has been used. With these constants absorption spectra are now calculated for the $C^{13}$-substituted carbonyls and in general very good agreement with experiment is found. The weak absorption bands observed in the carbonyls containing $C^{13}$ in natural abundance are accounted for in this way. Metal carbonyls of varying complexity such as $Ni(CO)_{4}, Cr(CO)_{6}, Fe(CO)_{5}$ and $Mn_{2}(CO)_{10}$ are treated. In some cases previous assignments of fundamentals as well as $C^{13}$ vibrations are corrected, in others new absorption bands are observed at very high concentrations. Since interaction constants in metal carbonyls are always found to be positive, the $C^{13}$ analogues of symmetric vibrations are shifted less than those of the corresponding antisymmetric vibrations. More quantitative estimates may be made through application of the sum rule