Tetrel bond is analysed for a series of ZF4 (Z = C, Si, Ge) complexes with one and two NH3 or AsH3 ligands. The MP2/aug-cc-pVTZ calculations were performed and supported by results of the Quantum Theory of “Atoms in Molecules” (QTAIM) and the Natural Bond Orbitals (NBO) approaches. The Z-tetrel atoms of complexes analysed interact through their σ-holes with nitrogen or arsenic Lewis base centre...

CASSCF calculated wavefunctions are presented for three f-element metallocenes, MCOT2 (M = Ce, Th, Pu; COT = η(8)-C8H8). The configurational admixture of these systems is investigated and, where the ThCOT2 ground state is well-defined as a monodeterminantal Th(IV) state, the cerocene ground state is found to be strong multiconfigurational and to bear strong similarities to that of plutonocene. ...

Substances known as nitrogen mustards turn into aziridinium ion through the intramolecular cyclization SN1. This ion reacts with the DNA preferably at the N7 position of the guanine, and because of this, it is an important antineoplastic agent. Based on this, the objective of this study is to quantify the interaction between the nitrogen mustard mechlorethamine and the guanine, using the NBO an...

The Structural theory of chemistry introduces chemical/molecular structure as a combination of relative arrangement and bonding patterns of atoms in a molecule. Nowadays, the structure of atoms in molecules is derived from the topological analysis of the quantum theory of atoms in molecules (QTAIM). In this context, a molecular structure is varied by large geometrical variations and concomitant...

the b3lyp/6-31++g** density functional calculations were used to obtain minimum geometries and interaction energies between the molecular hydrogen and nanostructures of fullerenes, c20 (cage), c20 (bowl), c19si (bowl, penta), c19si (bowl, hexa). the h2 molecule is set as adsorbed in the distance of 3å at vertical position from surface above the pentagonal and hexagonal sites of nanostructures. ...

The recent synthesis of a crystalline compound containing Ti bonded to cyclopentadienyl and a substituted dienyl fragment prompted the question of whether Ti-C contacts that were found to be shorter than other such bonded contacts in the same molecule should be considered as short nonbonded contacts or "nonclassical metal-to-saturated-carbon atom interactions", fitting the description of agosti...

An atom trapped in a crystal vacancy, metal cage, or fullerene might have many immediate neighbors. Then, the familiar concept of valency even coordination number seems inadequate to describe environment that atom. This difficulty terminology is illustrated here by four systems: H atoms tetragonal-pyramidal rhodium cages, an octahedral cobalt MgO hole, and C20 fullerenes. Density functional the...

equilibrium geometry, electronic structures, and vibrational modes of cob8- were investigated in the pbepbe/6-311+g(d,p) level of theory. the nucleus independent chemical shift (nics) analysis and magnetizability values were used for studying of aromaticity in cob8-. the effects of different solvents on the structure and frontier orbital energies were calculated using the polarizable continuum ...

A new, more flexible definition of fuzzy Voronoi cells is proposed as a computationally efficient alternative to Bader's Quantum Theory of Atoms in Molecules (QTAIM) partitioning of the physical space for large-scale routine calculations. The new fuzzy scheme provides atomic charges, delocalization indices, and molecular energy components very close to those obtained using QTAIM. The method is ...

The nature of the E-E' bonds (E, E' = S and Se) in glutathione disulfide (1) and derivatives 2-3, respectively, was elucidated by applying quantum theory of atoms-in-molecules (QTAIM) dual functional analysis (QTAIM-DFA), to clarify the basic contribution of E-E' in the biological redox process, such as the glutathione peroxidase process. Five most stable conformers a-e were obtained, after app...