Electronic Structure of Metal and Mixed Nonstoichiometric Clusters

Electronic Structure of Metal and Mixed Nonstoichiometric Clusters 

Sodium Fluoride and Lithium Hydride Clusters with 

AIMD = ab initio molecular dynamics B-LYP = Becke-Lee-Yang-Parr CVC = core-valence correlation DF = density functional LDA = local density approximation MCLR = multi-configurational linear response MP2 = Mpller-Plesset second order (MRD)CI = multi-reference double-excitation configuration interaction RPA = random phase approximation TD-MCSCF = time-dependent multi-configurational self-consistent field TD-SCF = time-depen-dent self-consistent field. 

Nanowires of simple metals (la or lb) represent another example where the control of the size and shape gives rise to new electrical and mechanical properties which can be useful for microelectronics. Periodic quantization steps in conductance found during elongation of short wires were assigned to the order-disorder state of layers of atoms connected with structural transformations predicted by molecular dynamics simulations.  

The above introductory remarks serve to point out the motivation and need for ab initio quantum chemical treatments of small pure and mixed metal clusters which allow for precise determination of their structural and electronic properties. 

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ELECTRONIC STRUCTURE OF METAL AND MIXED NONSTOICHIOMETRIC CLUSTERS... 

Electronic Structure of Metal and Mixed Nonstoichiometric Clusters 2 876... 

Articles specifically focusing on cluster chemistry, surface chemistry, and solids include those by Paul Bagus Surface Chemical Bond), Vlasta Bonacic-Koutecky Electronic Structure of Metal and Mixed Nonstoichiometric Clusters), and David Wales Water Clusters). 

We have shown that an interplay between quantum chemical predictions and experimental findings on optical response may offer complete information about structural and electronic properties of small metallic and mixed nonstoichiometric clusters as functions of their size and shape. Characteristic features of the studied systems are not smooth functions of their size. In other words, the properties of a small cluster with a given number of atoms can completely change by addition of a single atom. Cluster research is a field of... 

In the extreme class III behaviour,360-362 two types of structures were envisaged clusters and infinite lattices (Table 17). The latter, class IIIB behaviour, has been known for a number of years in the nonstoichiometric sulfides of copper (see ref. 10, p. 1142), and particularly in the double layer structure of K[Cu4S3],382 which exhibits the electrical conductivity and the reflectivity typical of a metal. The former, class IIIA behaviour, was looked for in the polynuclear clusters of copper(I) Cu gX, species, especially where X = sulfur, but no mixed valence copper(I)/(II) clusters with class IIIA behaviour have been identified to date. Mixed valence copper(I)/(II) complexes of class II behaviour (Table 17) have properties intermediate between those of class I and class III. The local copper(I)/(II) stereochemistry is well defined and the same for all Cu atoms present, and the single odd electron is associated with both Cu atoms, i.e. delocalized between them, but will have a normal spin-only magnetic moment. The complexes will be semiconductors and the d-d spectra of the odd electron will involve a near normal copper(II)-type spectrum (see Section 53.4.4.5), but in addition a unique band may be observed associated with an intervalence CuVCu11 charge transfer band (IVTC) (Table 19). While these requirements are fairly clear,360,362 their realization for specific systems is not so clearly established. 

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