摘要:

This paper describes theoretical calculations of the energy of low-lying, electronic states of CH2as functions of HCH angle. The method uses Hurley's modification of Moffitt's method of Atoms in Molecules to allow for intra-atomic electron correlation. The results are in agreement with experiment, giving a linear3Σg-ground state. The first excited state is a bent1A1state which lies no more than 0·6 ev above the ground state.

ISSN:0026-8976    

DOI:10.1080/00268976400100241

出版商:Taylor & Francis Group    

年代:1964

数据来源: Taylor

摘要:

It has been suggested [4] that an isotropicgvalue of 4·27 given by the high-spin ferric ion occurs becauseD= 0,E≠ 0 in a quadratic fine-structure spin-Hamiltonian. The plausibility of this interpretation is discussed and defended in the present paper. However, it is shown thatD= 0,E≠ 0 does not follow in any simple way from the symmetry of the environment, but probably arises through the effect of a ligand field on one of the excited4T1terms of the ferric ion. This is possible, providing the ligand field has a rather curious mixed symmetry.gvalues are given for the four doublets ofS= 7/2 whenD= 0,E≠ 0; they do not even possess axial symmetry.

ISSN:0026-8976    

DOI:10.1080/00268976400100251

出版商:Taylor & Francis Group    

年代:1964

数据来源: Taylor

摘要:

In quantum mechanical situations possessing symmetry, information may be obtained about degeneracies of states by considering the symmetry groupHconcerned. In the present paper it is shown that in certain cases extra information about matrix elements may be deduced by working in a suitably chosen larger groupGcontainingH. The situation is then said to possess a symmetry intermediate betweenHandG. Applications are made to ligand fields arising from octahedral and tetrahedral coordination, when the attached ligands are not necessarily all the same.

ISSN:0026-8976    

DOI:10.1080/00268976400100261

出版商:Taylor & Francis Group    

年代:1964

数据来源: Taylor

摘要:

An electron spin resonance absorption spectrum due to CO2-molecule-ions has been observed at 3 cm wavelength in single crystals of optical grade calcite. The spectrum exhibits orthorhombic symmetry with both the12C and13C isotopically substituted CO2-molecule-ions having the sameg-tensor components given bygzz= 2·00161,gxx= 2·00320 andgyy= 1·99727, wherezrefers to the carbonate-ion C-O bond direction,xthe crystal [111] direction andythe direction perpendicular to these two. The CO2-molecule-ions are located at carbonate-ion sites with their planes parallel to those of carbonate-ions and with their two-fold symmetry axes parallel to thezdirection. The hyperfine structure tensor components associated with the13C isotope areAzz= 177·28 oe,Axx= 134·62 oe, andAyy= 131·69 oe.

ISSN:0026-8976    

DOI:10.1080/00268976400100271

出版商:Taylor & Francis Group    

年代:1964

数据来源: Taylor

摘要:

Mit einem einzigen Variationsansatz werden die Energiekurven der Verbindungen H2, HeH+, He2++und LiH++für die Zustände1Σ und3Σ berechnet, sowie die der Einelektronenmoleküle H2+und HeH+. Die Ergebnisse werden in Form von Kurven angegeben, wobei auch der Zusammenhang zwischen den Parameteren des Variationsansatzes und dem Kernabstand graphisch dargestellt wird.

ISSN:0026-8976    

DOI:10.1080/00268976400100281

出版商:Taylor & Francis Group    

年代:1964

数据来源: Taylor

摘要:

The electron spin resonance spectrum of the NF2radical, trapped in argon and krypton matrices at 4·2°k, has been analysed to yield the isotropic contributions of the hyperfine interactions of both nitrogen and fluorine atoms. Effects due to anisotropy of theg-tensor have been observed from which we have calculated the principal values of theg-tensor. Theoretical estimates of the expected magnitudes of the principal values of theg-tensor have been made. These lead most readily to the interpretation of our experimental results for the radical trapped in an argon matrix with a matrix ratio ofM/R= 300, as indicating that at 4·2°kthe NF2radical is evidently rotating sufficiently freely about an axis perpendicular to the molecular plane to give ag-tensor which is apparently axially symmetrical.

ISSN:0026-8976    

DOI:10.1080/00268976400100291

出版商:Taylor & Francis Group    

年代:1964

数据来源: Taylor

摘要:

The absorption spectra of non-substituted, 2,5-dimethyl-, 2,5-di-tert-butyl-, trimethyl-, tetramethyl-p-benzosemiquinone ions have been measured. In alkaline ethylene glycol fairly stable semiquinone ions were prepared by an oxidation of hydroquinones or by a reduction of quinones at room temperature.

ISSN:0026-8976    

DOI:10.1080/00268976400100301

出版商:Taylor & Francis Group    

年代:1964

数据来源: Taylor

摘要:

The electronic structure ofp-benzosemiquinone ion is studied with the aid of the semi-empirical ASMO treatment including configuration interaction.

ISSN:0026-8976    

DOI:10.1080/00268976400100311

出版商:Taylor & Francis Group    

年代:1964

数据来源: Taylor

摘要:

It is pointed out that the absorption lines of the lanthanides that are peculiarly sensitive to changes in the ligands are consistent with the selection rules for quadrupole radiation within the 4f shell. A number of sources for this sensitivity are examined, and it is concluded that it owes its origin to the inhomogeneity of the dielectric. According to this mechanism, there is an asymmetrical distribution of the dipoles induced by the electromagnetic field in the medium surrounding a lanthanide ion. The variation across the lanthanide ion of the electric vector is very much greater than for the case of a homogeneous dielectric, and the intensities of quadrupole transitions are enormously enhanced.

ISSN:0026-8976    

DOI:10.1080/00268976400100321

出版商:Taylor & Francis Group    

年代:1964

数据来源: Taylor

ISSN:0026-8976    

DOI:10.1080/00268976400100331

出版商:Taylor & Francis Group    

年代:1964

数据来源: Taylor