Solid state quantum chemistry

A calculated band structure, with information about the position of the Fermi level, tell us a lot about the electric properties of the material under study (insulator, semiconductor, metal). They tell us also about basic optical properties, e.g., the band gap indicates what kind of absorption spectrum we may expect. We can calculate any measurable quantity, because we have at our disposal the computed wave function. 

However, despite this very precious information, which is present in the band structure, there is a little worry. When we stare at any band structure, such as that shown in Fig. 9.8, the overwhelming feeling is a kind of despair. All band structures look similar, well, just a tangle of plots. Some go up, some down, some stay unchanged, some, it seems without any reason, change their direction. Can we understand this What is the theory behind this band behaviour  

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A. A. Levin, Solid State Quantum Chemistry McGraw-Hill, New York (1977). 

Fermi Level and Energy Gap Insulators, Metals, and Semiconductors Solid-State Quantum Chemistry ( )... 

A masterpiece written by a Nobel Prize winner, one of the founders of solid-state quantum chemistry. Solid-state theory was traditionally the domain of physicists. Some concepts typical of chemistry, such as atomic orbitals, bonding and antibonding effects, chemical bonds, and localization of orbitals, were usually absent in such descriptions. They are highlighted in this book. 

The prototype molecule (or cluster ) approach to the quantum chemical treatment of extended systems has proved to be a valuable tool, especially if the chemical phenomenon of interest is mainly of local character. The prototype molecule models were used e.g. in the quantum chemistry of silicates [58], zeolites [59] and enzymes [14]. In the solid state, quantum chemistry calculations on prototype molecules [60] represent an important alternative to crystal orbital type methods. Although these latter calculations may be very important as starting points even for the description of local phenomena which violate the exact translational symmetry, the cluster approaches have the advantage of providing a direct space representation of the wave function. 

The prototype molecule (or cluster) approach to the quantum chemical treatment of relevant portions of extended systems is an important tool in the study of localized phenomena. For example, in solid state quantum chemistry this method offers a convenient way of treating surfaces or adsorbed molecules interacting with surfaces [177], crystal impurities, [178, 179], amorphous materials [180], and so on. 

We considered the basis sets for all-electron calculations in which all the core electrons are involved explicitly. Both in molecular and solid-state quantum chemistry the core states can be treated implicitly as creating an effective core potential (pseudopo-... 

Gubanov, V. A., Kurmaev, E. Z. Ivanovsky, A. L. (1984). Solid State Quantum Chemistry. Moscow Nauka. 

Ivanovsky, A. L. Anisimov, V. I. (1988). In ii All-Union Conference on Solid State Quantum Chemistry. Riga Publishing House of Latvian University, 144. Ivanovsky, A. L., Anisimov, V. I., Kurmaev, E. Z. Gubanov, V. A. (1988a). 

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