排序方式: 共有15条查询结果,搜索用时 0 毫秒
1.
Winfried Mientus Hans-Georg Bartel Werner Haberditzl Hans-Joachim Spitzer 《Monatshefte für Chemie / Chemical Monthly》1980,111(3):597-606
A normalization of the wave functions by means of the theoretical exact Multiple-Scattering-(MS)-formalism is discussed within the framework of the SCF-X-SW-method. For the atomic and extramolecular regions the integrals of normalization can be easily determined and the results can be described by the corresponding electronic charges. The calculation of the integral of the interatomic region is problematic. The needful volume integration is only necessary to theGreen's functions of the wave functions and can be solved by means of the residual theory. The further analytical calculation of the surface integrals leads to a complicated formalism which can be numerically evaluated. 相似文献
2.
3.
4.
Expressions are derived for the decomposition of tensorial properties into additive increments.In the second part of the paper calculations of H andC
H for LiH and of the susceptibilities for Li2, BH, HF, CO, F2, and LiF are presented. The contributions of the various LMO's to ,
P
andg-values are discussed. The results are compared to those obtained from coupledHF-perturbation theory and to experimental values where available. The values for are in good agreement with the experiment and—except for BH—with theHF-perturbation theory, however deviations are found in some molecules for andg-values and traced back to specific electronic features. 相似文献
5.
Winfried Mientus Werner Haberditzl Hans-Georg Bartel 《Monatshefte für Chemie / Chemical Monthly》1979,110(2):351-363
Based on the combination ofPars-Orbitals (PO) the LCPO-MO-Method has been described for the quantum chemical treatment of large molecules which are divided in reasonable fragments. The secular matrix constructed from the Eigenvalues and parameters of the molecular fragments has a characteristic block-form. The dimension of the secularproblem can be reduced and depends on the used approximations. The resulting method is demonstrated for naphthalene.
Herrn Professor Dr.O. E. Polansky zu seinem 60. Geburtstag gewidmet. 相似文献
6.
Cycloheptatrienemolybdenum tricarbonyl reacted with ligands (L) (L = phenyl-, o-tolyl-, m-tolyl-, p-tolyl-, α-naphthyl-, β-naphthyl-, sym-diphenyl-, sym-di-o-tolyl-, sym-di-p-tolyl, or sym-di-α-naphthyl-thiourea) to give Mo(CO)5L derivatives although the expected products were cis-Mo(CO)3L3. Evidence has been obtained for the formation of trans-Mo(CO)4L2 derivatives when L = sym-diphenyl- and sym-di-o-tolyl-thiourea. These donors on reaction with Mo(CO)4B (B = o-phenanthroline or 2,2′-bipyridine) yielded mixed ligand derivatives of the type Mo(CO)3BL. The appearance of three CO stretching bands is in agreement with the Cs symmetry of mixed-ligand molybdenum carbonyls. 相似文献
7.
Winfried Mientus Werner Haberditzl Hans-Georg Bartel Hans-Joachim Spitzer 《Monatshefte für Chemie / Chemical Monthly》1981,112(4):429-435
Based on the scattered-wave formalism the one-electron integrals have been investigated. It could be demonstrated that the integrals of the spheric-symmetrical regions can be determined conveniently. Caused by the complicated geometrical shape the contribution of the interatomic region to this integral was difficult to determine. A surface integral expression has been obtained as the solution which exact calculation will be very complicated and time consuming. Therefore a ZDO-analogous approximations are considered. By this means a formalism was derived which can be further reduced (simplified) and analysed relatively easily if a concrete operator is known. 相似文献
8.
W. Haberditzl 《Angewandte Chemie (International ed. in English)》1966,5(3):288-298
At the present state of instrumentation and quantum-mechanical approximations, diamagnetic measurements can supply information on chemical structure which complements the result of other approaches, such as infrared and NMR spectroscopy. General applicability and relatively low cost of equipment are among the advantages of this technique. There is growing interest in the relation to chemical shifts in NMR spectra and in the possibility offered by this technique for testing quantum-chemical approximations. 相似文献
9.
Ulrich Sternberg Klaus Salzer Harry Pfeifer Werner Haberditzl 《Monatshefte für Chemie / Chemical Monthly》1980,111(2):505-516
The procedure derived in1–6 was used to calculate the magnetic susceptibilities and the magnetic shielding of a series of diamagnetic molecules (CH4, C2H6, C2H4, C2H2, and HCN). The model requires only the knowledge of the unperturbed electron density. An incrementary treatment of the susceptibility-and shielding tensors is based on a partition of the electron density into localized parts.The values obtained by this procedure are in good agreement with experimental results in the case of susceptibilities and magnetic protonshieldings. The results for the13C-shielding however are not satisfactory. 相似文献
10.
Ulrich Sternberg Andreas Bleiber Wener Haberditzl Rainer Lochmann 《Molecular physics》2013,111(5):1159-1163
Using previously derived equations for the susceptibility [8] we calculated the components of the susceptibility tensor for ethene, benzene and naphthalene. Starting from PCILO bond orbitals and energy localized orbitals we evaluated theoretical increments for the susceptibility of the bonds building up these molecules. It was demonstrated that only with banana bonds was it possible to obtain satisfactory mean values and the right sign of the anisotropy, whereas a bond scheme with ∝ and π bonds yielded considerably worse values. The benzene value of X m=?712·6×10?12 m3 mol?1 resulted from a Kekulé structure with three a bonds and three pairs of r bonds and the naphthalene value of X m=?1137·4×10?12 m3 mol?1 from a similar bond scheme. 相似文献