Transition periodic electronic structures

In the last decade, quantum-chemical investigations have become an integral part of modern chemical research. The appearance of chemistry as a purely experimental discipline has been changed by the development of electronic structure methods that are now widely used. This change became possible because contemporary quantum-chemical programs provide reliable data and important information about structures and reactivities of molecules and solids that complement results of experimental studies. Theoretical methods are now available for compounds of all elements of the periodic table, including heavy metals, as reliable procedures for the calculation of relativistic effects and efficient treatments of many-electron systems have been developed [1, 2] For transition metal (TM) compounds, accurate calculations of thermodynamic properties are of particularly great usefulness due to the sparsity of experimental data. 

To understand what happens to the electron donated to the host, we have to consider the host s electronic structure. In transition metal chalco-genides or oxides, electron p orbitals from the chalcogen or oxygen overlap with s, p, and d orbitals from the transition metal, forming bonding and antibonding levels. The periodicity of the solid spreads... 

These properties of the d-shell chromophore (group) prove the necessity of the localized description of d-electrons of transition metal atom in TMCs with explicit account for effects of electron correlations in it. Incidentally, during the time of QC development (more than three quarters of century) there was a period when two directions based on two different approximate descriptions of electronic structure of molecular systems coexisted. This reproduced division of chemistry itself to organic and inorganic and took into account specificity of the molecules related to these classical fields. The organic QC was then limited by the Hiickel method, the elementary version of the HFR MO LCAO method. The description of inorganic compounds — mainly TMCs,— within the QC of that time was based on the crystal field... 

Electronic structure and the Periodic Table Transition elements... 

This process constitutes a kind of quantum jump, albeit not the neat quantum jump of an electron from one discrete energy state to another in an atom, we are dealing with highly composite, complex structures, and even when such structures are made up of units that operate on quantum principles, the aggregate may show various degrees of continuity. Recall the earlier discussion of individual differences. For certain individuals, the transition from a b-SoC to a d-ASC definitely shows a quantum jump, with no consciousness during the transition period. The system properties of the d-ASC are quite different from those of the b-SoC. 

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