Interplay between Theoretical Quantum Chemistry and Cold Atom Experiments

In this paper, we briefly summarize the new information which have been deduced on the atom–atom interaction from cold atom experiments. These information are quite unusual and very interesting. Their interpretation is considerably simplified if high quality quantum chemistry calculations are available. After an overview of the domain, we discuss in detail the experiments performed with metastable helium atom, thus showing the variety of new data obtained in this case and the importance of quantum chemistry calculations for their interpretation.     

Theoretical chemistry of gold. III

Gold is an element whose unique properties are strongly influenced by relativistic effects. A large body of appropriate calculations now exists and its main conclusions are summarized in this critical review. The present paper completes the recent reviews by Pyykk? (2004, 2005) (529 references).     

Spiroconjugation in 1-, 2-, and 3-Dimensions: The Foundations of a Spiro Quantum Chemistry

A recent paper has described the structure of a hypothetical 3-,4-connected net termed glitter. This is a model of an allotrope of carbon in the form of a synthetic metal. That paper pointed to the importance of through-space p interactions of adjacent olefin units in the net in understanding the electronic structure at the Fermi level. The present communication elucidates the role of spiroconjugation in understanding features of the electronic band structure and density of states of glitter. With this analysis of spiroconjugation in the 1-dimensional polyspiroquinoid polymer and the 3-dimensional glitter lattice, the foundations have been laid for a new type of quantum chemistry herein called spiro quantum chemistry. Spiro quantum chemistry complements traditional quantum chemistry which is focused on linear polyenes, circular annulenes, polyhexes, 2-dimensional graphene sheets and related structures including fullerenes, by focusing on spiroconjugated hydrocarbon structures in 1-, 2- and 3-D, including linear spiro[n]quinoids and polyspiroquinoid in 1-D, circular cyclospiro[n]quinoids, spiro[m,n]graphene fragments and spirographene in 2-D and [m,n,o]glitter fragments and glitter in 3-D.     

Spin-Free Quantum Chemistry. XXI. Hartree–Fock theory

The theory of the open-and closed-shell restricted Hartree–Fock method is given a unitary group formulation. Both extremum and stability conditions are employed, the former leading to a generalized Brillouin theorem.     

Differential geometry based solvation model. III. Quantum formulation

Solvation is of fundamental importance to biomolecular systems. Implicit solvent models, particularly those based on the Poisson-Boltzmann equation for electrostatic analysis, are established approaches for solvation analysis. However, ad hoc solvent-solute interfaces are commonly used in the implicit solvent theory. Recently, we have introduced differential geometry based solvation models which allow the solvent-solute interface to be determined by the variation of a total free energy functional. Atomic fixed partial charges (point charges) are used in our earlier models, which depends on existing molecular mechanical force field software packages for partial charge assignments. As most force field models are parameterized for a certain class of molecules or materials, the use of partial charges limits the accuracy and applicability of our earlier models. Moreover, fixed partial charges do not account for the charge rearrangement during the solvation process. The present work proposes a differential geometry based multiscale solvation model which makes use of the electron density computed directly from the quantum mechanical principle. To this end, we construct a new multiscale total energy functional which consists of not only polar and nonpolar solvation contributions, but also the electronic kinetic and potential energies. By using the Euler-Lagrange variation, we derive a system of three coupled governing equations, i.e., the generalized Poisson-Boltzmann equation for the electrostatic potential, the generalized Laplace-Beltrami equation for the solvent-solute boundary, and the Kohn-Sham equations for the electronic structure. We develop an iterative procedure to solve three coupled equations and to minimize the solvation free energy. The present multiscale model is numerically validated for its stability, consistency and accuracy, and is applied to a few sets of molecules, including a case which is difficult for existing solvation models. Comparison is made to many other classic and quantum models. By using experimental data, we show that the present quantum formulation of our differential geometry based multiscale solvation model improves the prediction of our earlier models, and outperforms some explicit solvation model.     

Henryk Chojnacki,Prof. Dr Hab. (Quantum Chemistry)

Structural Chemistry -     

著名量子化学家歇弗尔

经国务院学位委员会批准,最近北京理工大学授予亨利·弗·歇弗尔(Henry F.Schaefer Ⅲ)教授名誉博士学位荣誉称号.在此之前,经教育部批准,北京师范大学也授予他名誉教授荣誉称号,以表彰他在量子化学研究领域中取得的卓越成就和为促进中美两国在计算量子化学领域的合作中所作的贡献.     

Phosphorus Chemistry. III Preparation of Vinyl Deuterated Trisubstituted Alkenes

A facile procedure for the preparation of vinyl deuterated trisubstituted alkenes via reduction of the corresponding (2-oxoalkyl)triphenyl-phosphonium halides with sodium borodeuteride is described.