A generalised model and calculation of the hyperfine interaction constant for anomalous muonium in the crystalline lattice of silicon

A new microscopic model of anomalous muonium for the elemental semiconductors is proposed. The relevant configuration consisting of both a diamagrentic molecule Si−Mu and an unpaired orbital e⁻ is contained into a semivacancy of the real lattice. By using the unrestricted Hartree-Fock computational method the principal properties of the system are established. A dynamical version of the model together with a question on the formation of such system are discussed.     

Use of ab initio pseudopotentials for the assignment of boundary conditions of clusters modeling MgO

Conclusions The work reported in this article was aimed at determining the feasibility and desirability of using ab initio core pseudopotential anionic centers and cluster models of ionic crystals of the type of a cluster implanted in a crystal. The results presented herein, from calculations of a number of clusters of magnesium oxide, demonstrate the promise of this approach for compensation of bond rupture effects. In particular, such a model offers a means for a substantial reduction of the artifact-introduced nonequivalence of the partial ionic densities and the effective charges. The comparatively high reliability of the cluster scheme proposed in this work is also supported by results from calculations of the geometric parameters of the crystal.Branch of Institute of Chemical Physics, Russian Academy of Sciences. Institute of Chemistry of Natural Organic Raw Materials, Siberian Branch, Russian Academy of Sciences. Translated from Zhurnal Strukturnoi Khimii, Vol. 33, No. 2, pp. 3–7, March–April, 1992.     

Programming package “ESCAPAK” for calculations of electronic structure,adapted for the ES series computers

Branch of the Institute of Chemical Physics, Academy of Sciences of the USSR. Translated from Zhurnal Strukturnoi Khimii, Vol. 30, No. 3, pp. 132–134, May–June, 1989.     

SCF discrete-variational Xα calculations of the NH4Cl Auger spectrum

Formalism for calculations of the singlet and triplet Auger energies within the Xα model is presented. Using this method the KVV Auger spectrum of NH₄Cl is calculated and the theoretical intensities are determined within a one-center approximation. The calculated spectrum reproduces quite well all the main features observed for solid NH₄Cl. A new interpretation of the spectrum is suggested.     

Negative ions of transition metal-halogen clusters

A systematic density functional theory based study of the structure and spectroscopic properties of neutral and negatively charged MX(n) clusters formed by a transition metal atom M (M=Sc,Ti,V) and up to seven halogen atoms X (X=F,Cl,Br) has revealed a number of interesting features: (1) Halogen atoms are bound chemically to Sc, Ti, and V for n≤n(max), where the maximal valence n(max) equals to 3, 4, and 5 for Sc, Ti, and V, respectively. For n>n(max), two halogen atoms became dimerized in the neutral species, while dimerization begins at n=5, 6, and 7 for negatively charged clusters containing Sc, Ti, and V. (2) Magnetic moments of the transition metal atoms depend strongly on the number of halogen atoms in a cluster and the cluster charge. (3) The number of halogen atoms that can be attached to a metal atom exceeds the maximal formal valence of the metal atom. (4) The electron affinities of the neutral clusters abruptly rise at n=n(max), reaching values as high as 7 eV. The corresponding anions could be used in the synthesis of new salts, once appropriate counterions are identified.