Low-lying intrinsic energy levels in the nucleus170Ho

The band-head energies of the two-quasiparticle states expected in the doubly odd deformed nucleus¹⁷⁰Ho are calculated for a zero range residual interaction. The results are compared with the available experimental information. It is concluded that the ground state has the Nilsson configuration 6⁺{7/2^?[523↑] _p }+5/2[512↑] _n being the 2.76m isomer whereas the 43s isomer is the 1⁺ ∑=0 state arising from the same configuration and lies at about 100 keV excitation energy in agreement with the experiment. The first excited state in this nucleus is predicted to be the 4^?{3/2⁺[411↑] _p +5/2^?[521↑] _n } state close to the ground state with the corresponding 1^? ∑=0 member expected to appear well above the 1⁺ isomer.     

Low-lying energy levels in 166Ho

The properties of some low-excited states of ¹⁶⁶Ho have been studied using thin, high resolution Ge detectors. The relative intensities of γ-lines were determined. The directional angular correlation measurements for the 28.23–54.24 keV cascade are in agreement with the 1^?(M1)2^?(E2)0^? spin sequence. The magnetic moment μ = 0.068 ± 0.010 μ_N of the 54.24 keV level was determined by integral perturbed angular correlation (IPAC) in an external magnetic field. This value can be explained by the configuration mixing due to the Coriolis interaction.     

Classification of energy levels of the isopropanol molecule

Using the methods of a symmetry group chain, an energy level classification is constructed for the nonrigid isopropanol molecule (CH₃)₂CHOH in the ground electronic state with an allowance for the internal motion of hydroxyl and two methyl tops.     

Classification of the energy levels of the cyclopentane molecule

The energy levels of the cyclopentane molecule are classified taking into account pseudorotation and inversion motion caused by the nonplanarity of the equilibrium configuration of the five-membered cycle of the carbon nuclei of the molecule. For this purpose, the relatively recently developed symmetry-group chain methods, which are the most powerful methods at present, are used.     

On the study of the vibrational energy levels of Arsine molecule

We compare two formalisms applied to the vibrational modes of the molecule of AsH₃ of C_3v molecular symmetry group. Indeed, the close stretching modes of this molecule may be considered as those of a three-dimensional oscillator whereas the bending modes may be considered either as a one-dimensional oscillator of symmetry A₁ and a two-dimensional oscillator of symmetry E or as an approximate three-dimensional oscillator. So, we have applied the U(p + 1) formalism to the both stretching and bending modes and introduced coupling terms acting on an appropriate coupled vibrational basis through a local mode formalism. We have then compared the result of our fitting with those obtained with the coupling of a local mode formalism adapted to the stretching vibrations with a normal mode formalism for the bending ones. Finally we compare our results with other methods recently proposed in the literature.     

Low-lying electronic states of LiF molecule with inner electrons correlation

The potential energy curves and dipole moments of the low-lying electronic states of LiF molecule are performed by using highly accurate multi-reference configuration interaction with Awcv5z basis sets. 1s, the inner shell of Li is considered as the closed orbit, which is used to characterise the spectroscopic properties of a manifold of singlet and triplet states. 16 electronic states correlate with two lowest dissociation channels Li(²S)+F(²P) and Li(²P)+F(²P) are investigated. Spectroscopic parameters of the ground state X¹Σ⁺ have been evaluated and critically compared with the available experimental values and the other theoretical data. However, spectroscopic parameters of 1³Π, 1¹Δ, 1¹Σ^?, 1¹Π, 1³Σ⁺, 2³Σ⁺, 1³Δ, 1³Σ^?, 2³Π, 2¹Π, 3³Π, 3¹Π and 3³Σ⁺ states are studied for the first time. These 13 excited states have shallow potential wells, and the dispersion coefficients of these excited states are predicted. In additional, oscillator strengths of excited states at equilibrium distances are also predicted.     

Low-lying exciton levels in a strong magnetic field

The behavior of the n = 2 and n = 3 exciton levels in a strong magnetic field is analyzed for the case in which the spacing between the Coulomb levels is much greater than that between Landau levels. The results are compared with experimental data on magnetooptical absorption in Cu₂O. The observed splitting of these levels can be attributed to the appearance of a Landau series above the Coulomb levels.Translated from Izvestiya VUZ. Fizika, No. 2, pp. 7–11, February, 1970.     

Low-lying levels of 140Pr

The doubly odd nucleus ¹⁴⁰Pr has been investigated by means of the ¹⁴¹Pr(d, t)¹⁴⁰Pr and ¹⁴⁰Ce(p, nγ)¹⁴⁰Pr reactions. Twenty-eight levels, up to 1300 keV excitation, were observed in the pickup study. DWBA analysis was used to determine l-values and spectroscopic factors for all but a few which are very weakly populated. Gamma-ray angular distributions, measured at E_p = 4.78 MeV for the five strongest γ-rays, show appreciable nuclear alignment and demonstrate the feasibility of such experiments in this mass region. Taken together, the two studies have permitted the identification of the 12 levels expected from the low-lying ($\text{π2}\text{d}{}_{\mathrm{<mtext>5</mtext><mtext>2</mtext>}}\text{ν2}\text{d}{}_{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}{}^{\mathrm{?1}}$), ($\text{π2}\text{d}{}_{\mathrm{<mtext>5</mtext><mtext>2</mtext>}}\text{ν3}\text{s}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}{}^{\mathrm{?1}}$), ($\text{π1}\text{g}{}_{\mathrm{<mtext>7</mtext><mtext>2</mtext>}}\text{ν2}\text{d}{}_{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}{}^{\mathrm{?1}}$) and (π1g_{$\text{7}\text{2}$}ν3s_{$\text{1}\text{2}$}^?1) configurations. Tenta assignments for the strong odd-parity states are suggested on the basis of their spectroscopic factors.     

Low-lying levels in the nuclei151Nd and155Sm

Decay properties of excited states in the¹⁵¹Nd and¹⁵⁵Sm nuclei produced by 10 MeV douterons have been investigated with in-beam gamma-gamma-coincidence equipment during bombardment of the¹⁵⁰Nd and¹⁵⁴Sm targets. The results largely confirm the data obtained earlier for these nuclei. The (d, p γ) reaction channel favors population of odd-parity low-spin levels, whose energies follow the rule of regular band structure for well-deformed nuclei. The level schemes are interpreted with calculations using an axial particle-rotor model with a Woods-Saxon potential.     

Low-lying levels in103Rh from Coulomb excitation

Five low-lying negative parity states of¹⁰³Rh up to 1277 keV excitation energy were observed to be Coulomb excited with 2·5–4·5 MeV protons. The de-excitation gamma rays from these levels were identified in the singles spectra recorded with a 57 cc Ge(Li) detector. The level energies, branching ratios, reduced transition probabilitiesB(E2) and the multipole mixing ratios () were obtained. The 880, 1106 and 1277 keV levels have been Coulomb excited with protons for the first time. The ambiguity in theJ values for 803 and 1106 keV levels have been resolved using ²-fits, the assigned spin values are 1/2^– and 5/2^–, respectively. The-values for 474·1 and 811·2 keV transitions were obtained for the first time. The results have been discussed in the light of previously reported results.The authors wish to thank Professor I. M. Govil for his active interest at various stages of this work. One of us (DCT) acknowledges the financial support from U.G.C., New Delhi, under Faculty Improvement Programme.     

Low-lying levels of201Hg from the decay of201Au

The decay of 26.4-min²⁰¹Au has been investigated using chemically separated sources and Ge(Li), Si(Li), plastic and Nal(Tl) detectors in different singles and coincidence arrangements. The β-disintegration energy was measured to be 1.27 ± 0.10 MeV. Thirteen γ-rays were observed to belong to this decay and the new levels at 543, 549.2, 552.8, 559.1, 605.7, 645.4, 732 and 1188 keV were established in²⁰¹Hg, in addition to the three previously known excited states below 200 keV.     

线性三原子分子转动-振动能谱的李群处理方法

本文利用李代数方法与二次量子化理论计算了线性三原子分子的转动-振动能谱.结果表明,如果将分子的转动与振动均看作是谐振子,则可以导致这种分子的转动-振动能谱公式.     

Perturbations in the vibration-rotation-torsion energy levels of an ethane molecule exhibiting internal rotation splittings

Various examples of perturbations in the vibration-rotation-torsion energy levels of an ethane molecule exhibiting internal rotation splittings are discussed, both from the point of view of the point group D_3d, appropriate when internal rotation tunneling effects cannot be observed, and from the point of view of the group $\text{G}{}_{36}{}^2$, appropriate when internal rotation tunneling in ethane leads to observable splittings in the spectrum. It is found, for perturbations allowed in both D_3d and $\text{G}{}_{36}{}^2$, that each of the two torsional components of the perturbed D_3d vibration-rotation level can in principle interact with a “corresponding” torsional component in the perturbing vibration-rotation level. It is found for perturbations forbidden in D_3d but allowed in $\text{G}{}_{36}{}^2$, which all occur between D_3d vibrational levels of different g, u parity, that only one of the two torsional components of the perturbed D_3d vibration-rotation level can interact with a corresponding torsional component in the perturbing vibration-rotation level. Some of the perturbations examined give intensity to otherwise forbidden transitions in such a way that perturbation-induced transitions can be used in conjunction with normally allowed transitions to determine the sum of the internal rotation splittings for two rotational levels differing in K by three units.     

Low-lying levels and high-spin band structures in 102Rh

Levels in ¹⁰²Rh have been populated in the reaction ⁷⁰Zn+³⁶S at 130 MeV. The level structure of ¹⁰²Rh has been investigated using the EUROGAM II array. Low-lying states and four high-spin bands have been identified. The configurations of low-lying levels and two-quasiparticle bands are interpreted in the frame of the interacting boson-fermion-fermion model. The four observed band structures are also compared with cranked shell model calculations using a modified oscillator potential.     

Low-lying levels in 194Os and the prolate—oblate phase transition

Gamma-rays have been observed deexciting the 2⁺₁ and 2⁺₂ levels in ¹⁹⁴Os following two-fold neutron capture on ¹⁹²Os using the high-resolution bent crystal spectrometers and high neutron flux available at the ILL. The results indicate that rather different structural changes take place in the osmium and the platinum nuclei, and that the prolate-oblate transition occuring near ¹⁹²Os leads to a substantially developed oblate character in ¹⁹⁴Os.     

Calculation of vibrational energy levels of water molecule by summing divergent perturbation theory series

The Rayleigh-Schrödinger perturbation theory is applied to a calculation of vibrational energy levels of the H₂O molecule for isolated states and the states involved in the anharmonic Fermi and Darling-Dennison resonances. It is shown that in spite of the rapid divergence of the perturbation theory series caused by the resonances, the use of the summation methods of Padé, Padé-Borel, and Padé-Hermite and the moments method allows one to obtain quite satisfactory results.     

The rotation-torsion energy levels of the methanol molecule 12CH3 16OH above the triple potential barrier

A high-resolution spectrum of the methanol molecule has been recorded between 720 and 1000 cm⁻¹ with a long-path Fourier transform spectrometer. Twenty-three torsional subbands have been identified. Analysis of these subbands has led to the first determination of rotational constants for torsional levels with n = 3 or n = 4, lying above the potential barrier. The subband centers combined with microwave and far-infrared data of previous investigators allowed determination of the CH₃ and OH moments of inertia, the barrier height, and the Kirtman perturbation constants.     

Estimation of dissociation energy of the AsS molecule

Experimental potential energy curve for the X²Π state of AsS has been constructed using the method of Rydberg-Klein-Rees. The precise dissociation energy for the ground state has been estimated as 4.150±0.13 eV by the curve fitting procedure. The first ionization potential of the AsS molecule is found to be 8.66 eV.