Zobrazeno 1 - 10
of 15
pro vyhledávání: '"Georgi St. Nikolov"'
Publikováno v:
International Journal of Quantum Chemistry. 113:723-728
DFT periodic, ONIOM, and cluster studies with all-electron basis sets are applied to Cu(I) exchanged zeolites and silicoalumino-phosphate analogs with faujasite and chabazite topology. The reactivity of the cations at different cation positions is pr
Publikováno v:
The Journal of Physical Chemistry B. 108:13200-13207
The vibrational modes of double six-member ring (D6R) clusters with general composition (Mn+)x/nH12Si12-xAlxO18 (where x = 0, 2; M = H+, Li+, Na+, K+, Ca2+) are studied by DFT with the B3LYP method. The point group symmetry of the fragments with Si,A
Publikováno v:
ChemPhysChem. 5:192-201
The 3d-transition-metal dioxo-, peroxo-, and superoxoclusters with the general composition MO 2 , M(O 2 ), and MOO (M=Mn, Fe, Co, and Ni) were studied by DFT by the B1LYP functional. The dioxides in their ground states represent the global minima for
Publikováno v:
The Journal of Physical Chemistry A. 106:4104-4114
The stationary points on the potential energy surfaces (PES) of cobalt oxide clusters were studied by the density functional theory, with the B1LYP exchange-correlation functional. A number of local minima were detected on the doublet, quartet, and s
Publikováno v:
Monatshefte fuer Chemie/Chemical Monthly. 132:339-348
The mechanism of the keto-enol interconversion of pentane-2,4-dione (trivial name: acetylacetone, acac) was examined at the restricted Hartree-Fock (HF) level and the DFT correlation functional BLYP method using the 6-311G** basis, both included in t
Publikováno v:
The Journal of Physical Chemistry B. 104:7299-7305
The vibrational modes of double four-member ring fragments (D4R) of the general composition [Mx]x+[H8Si8-xAlxO12]x-, where Si and Al occupy tetrahedral sites, 0≤ x ≤ 4, and M+ is a monovalent charge-compensating cation, are assigned to the framew
Publikováno v:
The Journal of Physical Chemistry A. 104:5302-5306
The electronic structure and relative stability of [H8Si8-xAlxO12]x- structural fragments with Si and Al atoms located at tetrahedral sites and connected by bridging oxygen atoms so as to form a tetragonal prism, together with oxygen-coordinated char
Publikováno v:
Journal of Molecular Structure: THEOCHEM. 499:35-50
Ab initio calculations were carried out on the species resulting from the co-ordination of molecular oxygen to two Cu(I) centres. The calculations were performed at the HF and QCISD(T) levels with different sets of wave functions (a) STO-3G ∗∗ ;
Autor:
Georgi St. Nikolov, Vassil B. Delchev
Publikováno v:
Monatshefte fuer Chemie/Chemical Monthly. 131:107-115
Malonaldehyde rotamer geometries were optimized using ab initio calculations at the HF level with STO-3G** and 6-21G** basis sets. The most stable rotamer is the ω-shaped one with cyclic structure and intramolecular hydrogen bond. The most unstable
Autor:
Vassil B. Delchev, Georgi St. Nikolov
Publikováno v:
Monatshefte fuer Chemie/Chemical Monthly. 131:99-105
The mechanism of the keto-enol tautomerism of malonaldehyde was studied by ab initio methods using 6-21G** and 6-311G** basis functions at the HF level. Two separate mechanisms were examined: through-space proton transfer in the ω-shaped form and th