Electronic structures of square planar coordinated transition metal ions in BaCuSi4O10 and CaCrSi4O10 are investigated using the ligand-field theory(LFT),angular overlap model(AOM) and iterative extended Hueckel molec...Electronic structures of square planar coordinated transition metal ions in BaCuSi4O10 and CaCrSi4O10 are investigated using the ligand-field theory(LFT),angular overlap model(AOM) and iterative extended Hueckel molecular orbital theory(IET).The electronic energy levels of the natural mineral dioptase are also investigated,in which the Cu^2+ ions occupy the sites of pseudo D4h symmetry,Both LFT and AOM predict that the crystal-field levels of transition metal ions in these compounds follow such an order that E(2B1g)<E(2B2g)<E(2A1g)<E(2Eg),and the frequencies of the crystal-field transitions obtained from point charge calcuations are in good agreement with those observed.However,the energy-level order cannot be determined unambiguously from the IET calculation because it depends on the values of parameters chosen for the calculation.展开更多
In this paper several methods including MNDO, multiple scattering Xa and ab initio self-consistent-field MO theories have been used to calculate the minimum energy geometries, force constants, vibrational frequencies,...In this paper several methods including MNDO, multiple scattering Xa and ab initio self-consistent-field MO theories have been used to calculate the minimum energy geometries, force constants, vibrational frequencies, and 11B quadruple coupling constants of B-O polyhedra such as [BO3], [BO4], [OB2]and [OB3]. The results are in good agreement with the experimental and calculated values so far published by other authors.展开更多
Reported in this paper are the expressions for the crystal field potential energy and perturbation matrix elements for the symmetry of C4v, D2h and Ci, by which the crystal field spectra of Cu^2+ ions in the minerals ...Reported in this paper are the expressions for the crystal field potential energy and perturbation matrix elements for the symmetry of C4v, D2h and Ci, by which the crystal field spectra of Cu^2+ ions in the minerals such as metatorbernite, conichalcite and turquoise have been calculated. In our calculation, the values uf (r^3) and (r^4)are determined by the empirical radial-wave function cited from reference [1]. The results obtained are essentially consistent with the experimental data.展开更多
文摘Electronic structures of square planar coordinated transition metal ions in BaCuSi4O10 and CaCrSi4O10 are investigated using the ligand-field theory(LFT),angular overlap model(AOM) and iterative extended Hueckel molecular orbital theory(IET).The electronic energy levels of the natural mineral dioptase are also investigated,in which the Cu^2+ ions occupy the sites of pseudo D4h symmetry,Both LFT and AOM predict that the crystal-field levels of transition metal ions in these compounds follow such an order that E(2B1g)<E(2B2g)<E(2A1g)<E(2Eg),and the frequencies of the crystal-field transitions obtained from point charge calcuations are in good agreement with those observed.However,the energy-level order cannot be determined unambiguously from the IET calculation because it depends on the values of parameters chosen for the calculation.
文摘In this paper several methods including MNDO, multiple scattering Xa and ab initio self-consistent-field MO theories have been used to calculate the minimum energy geometries, force constants, vibrational frequencies, and 11B quadruple coupling constants of B-O polyhedra such as [BO3], [BO4], [OB2]and [OB3]. The results are in good agreement with the experimental and calculated values so far published by other authors.
文摘Reported in this paper are the expressions for the crystal field potential energy and perturbation matrix elements for the symmetry of C4v, D2h and Ci, by which the crystal field spectra of Cu^2+ ions in the minerals such as metatorbernite, conichalcite and turquoise have been calculated. In our calculation, the values uf (r^3) and (r^4)are determined by the empirical radial-wave function cited from reference [1]. The results obtained are essentially consistent with the experimental data.