Quantum information topological

Database a web-based tool using quantum chemical topology to predict bioisosteric replacements for drug design. Journal of Chemical Information and Modeling, 49 (6), 1497-1513. 

Many systems are being studied to manipulate quantum information. Some make use of individual atoms cold trapped ions, neutral atoms in optical lattices, atoms in crystals. Other involve particle spins or photons in cavity QED or nonlinear optical setups as well as more exotic ones where geometric combinations of elementary excitations are defined as qubits, such as in topological quantum computing [8]. However, none of these systems has yet emerged as a definitive way to build a quantum information processor. A reason for this is that there is an essential dichotomy we need... 

Kauffman, L.H., Lomonaco, Jr., S.J. Entanglement Criteria - Quantum and Topological. In Donkor, Pinch, Brandt, (eds.) Quantum information and computation-Spie Proceedings, 21-22 April, 2003, Orlando, FL, vol. 5105, pp. 51—58 (2003)... 

The basic theories of physics - classical mechanics and electromagnetism, relativity theory, quantum mechanics, statistical mechanics, quantum electrodynamics - support the theoretical apparatus which is used in molecular sciences. Quantum mechanics plays a particular role in theoretical chemistry, providing the basis for the valence theories which allow to interpret the structure of molecules and for the spectroscopic models employed in the determination of structural information from spectral patterns. Indeed, Quantum Chemistry often appears synonymous with Theoretical Chemistry it will, therefore, constitute a major part of this book series. However, the scope of the series will also include other areas of theoretical chemistry, such as mathematical chemistry (which involves the use of algebra and topology in the analysis of molecular structures and reactions) molecular mechanics, molecular dynamics and chemical thermodynamics, which play an important role in rationalizing the geometric and electronic structures of molecular assemblies and polymers, clusters and crystals surface, interface, solvent and solid-state effects excited-state dynamics, reactive collisions, and chemical reactions. 

Multiple-quantum correlation spectra provide information about through-bond connectivities as all COSY type experiments do. In addition, direct topology information is also available from the same spectrum through remote and combination peaks [5]. Correlation peaks between spins with small chemical shift difference can be examined, too, since there are no diagonal peaks. In this sense, a correlation of MQ coherences with those... 

Chemical information can be expressed in a number of ways. Chemical descriptors are commonly used in QSAR. There are thousands of chemical descriptors possibly used in QSAR. Indeed, programs such as DRAGON and CODESSA, just to name a couple, can calculate thousands of parameters [7, 8]. Chemical descriptors have different complexities. Some of them do not require any information on the structure, such as molecular weight. Others refer to the bidimensional structure, such as the number of double bonds. While some others require tridimensional information, such as molecular volume. Chemical descriptors can be geometrical, topological, quantum-mechanical, electrostatical, etc. There are a few books describing chemical descriptors [7, 8],... 

These summarize topological information about a molecule with atomic properties [39]. A molecular E-state index is expressed as a sum of atomic E-state indices, which are composed of two parts. First is the intrinsic atomic part, and second is perturbation, which depends on its neighborhood (other atoms in the structure). The intrinsic part includes information about the a- and 7r-orbitals, lone pairs, hydrogen atoms attached to heavy atoms, and the principal quantum numbers of valence electrons. The perturbation part is a sum of all other atomic parts modified by fimction, which descends with distance. 

Electronic information is combined with shape and steric information to characterize molecules in - charged partial surface area descriptors. Other approaches, different from those closely related to quantum-chemistry, refer to electronic descriptors, such as - electronic substituent constants, - electrotopological state indices, -> topological charge indices. - Reactivity indices and - resonance indices are also related to electronic descriptors. 

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