Quadrupole correction

Basing on the nuclear shell-model and concentrating on the monopole,pairing and quadrupole corrections originating from the nucleon-nucleon force,both the appearance of low-lying 0+ intruder states near major closed shell (Z=50, 82)and sub-shell regions (Z=40,64) can be described.Moreover,a number of new facets related to the study of intruder states are presented. 

Bundgen P, Grein F and Thakkar A J 1995 Dipole and quadrupole moments of small molecules. An ab initio study using perturbatively corrected, multi-reference, configuration interaction wavefunctions J. Mol. Struct. (Theochem) 334 7... 

Through the use of sequential electric (electrostatic) and magnetic fields (sectors) and various correcting lenses, the ion beam leaving the ion source can be adjusted so that it arrives at the collector in focus and with a rectangular cross-section aligned with the collector slits. For the use of crossed electromagnetic fields. Chapter 25 ( Quadrupole Ion Optics ) should be consulted. 

Norma ions (m, or formed in the ion source will pass (filter) through the first, second, and third quadrupoles (Ql, 2, 3) if these are set correctly. If Ql is set to pass only m, ions, then normal mj ions cannot reach the detector, and if Q3 is set to pass only mj ions, then m + ions cannot reach the detector. Any mj ions that reach the detector must have been formed (metastable or induced by collision) by dissociation of m,+ ions in Q2. 

At the molecular level, electric quadrupoles can lead to useful structural information. Thus, whilst the absence of a permanent electric dipole in CO2 simply means that the molecule is linear, the fact that the electric quadrupole moment is negative shows that our simple chemical intuition of 0 C" 0 is correct. The definition of quadrupole moment is only independent of the coordinate origin when the charges sum to zero and when the electric dipole moment is zero. 

In order to find the correct quantum-mechanical energies for a nuclear quadrupole in an electric field gradient, we need to... 

Quadrupole splittings are often interpreted from ligand field models with simple rules for the contributions from each occupied f-orbital (see discussion above). However, these models fail even qualitatively in the case of more covalent metal-ligand bonds. An example concerns the quadrupole spUttings of Fe(IV)-oxo sites in their 5 = 1 or 5 = 2 spin states. Here, ligand field considerations do not even provide the correct sign of the quadrupole splitting [60]. 

Figure 3. Dependence of analyte ion intensity on concentration. (A) Dependence of total current / on concentration M = mol/L of analyte ion, (Morphine)H+, i.e., MorH+, in solution. (B) Dependence of mass-analyzed MorH+ ion current in counts/s on MorH+ concentration. At low MorH+ concentrations, [MorH+] < 1CT6 M, the dominant electrolyte in the solution are impurity ions Na+ and NH4. In this region MorH+ intensity is proportional to [MorH+] in solution. Mass-analyzed ion intensity was corrected for mass-dependent transmission Tm, of quadrupole. Concentration of morphine hydrochloride given in mol/L (M). From Kebarle, P. Tang, L. Anal. Chem. 1993, 65, 973A, with permission.

Dr. Erickson Dr. CliflFord, did I interpret your talk and slides correctly to mean that you found large quadrupole splittings for iron in some of the rare earth oxides ... 

Table 2. LiH dipole and quadrupole polarizability (in atomic units) for the vibrational ground state u = 0 calculated with different response theory methods. P(Pe) is the value at the minimum of the potential energy curve, Pq o is the value in the vibrational ground state and ZPVC = Pq o P(Pe) is the corresponding zero-point-vibrational correction...

In Table 7 we compare the ZPVCs for the dipole and quadrupole polarizabilities of HF. In the same way as for LiH, we have calculated the vibrational averages for each method with two different wavefunctions - one obtained from the PEC of the same or related method as used in the calculation of the property curve and the other obtained from the loo CAS PEC. Compared with the equivalent results for LiH we observe significant differences between the calculations on the two molecules. Eirst of all the vibrational corrections are smaller than in LiH but roughly in the same ratio as the polarizabilities. The influence of the PEC is larger than in LiH. 

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