Structure-activity methods quantum chemistry

The SPARC (Sparc Performs Automated Reasoning in Chemistry) approach was introduced in the 1990s by Karickhoff, Carreira, Hilal and their colleagues [16-18]. This method uses LSER [19] to estimate perturbed molecular orbitals [20] to describe quantum effects such as charge distribuhon and delocalizahon, and polarizability of molecules followed by quanhtative structure-activity relationship (QSAR) studies to correlate structure with molecular properties. SPARC describes Gibbs energy of a given process (e.g. solvation in water) as a sum of ... 

The paper [8] includes results of investigating electron mechanisms of the impact of active particles, radicals, hydrated electrons artificially generated by plasma on the behavior of cyanide complexes of zinc in water solutions. The above investigation was conducted using quantum chemistry methods. Quantum-chemical calculation of electron structure of the complexes Zn(CN)42 4EP-20H- with complete optimization of all geometric parameters [9] was performed. 

When the temperature ranges of k and k- data are not approximately coincident, it may be necessary to correct the activation parameters to the same mean temperature by using heat capacity data. This correction can be estimated by statistical mechanics, after finding (e.g., by quantum chemistry methods) a structure for the activated complex. 

Quantum-chemical cluster models, 34 131-202 computer programs, 34 134 methods, 34 135-138 for chemisorption, 34 135 the local approach, 34 132 molecular orbital methods, 34 135 for surface structures, 34 135 valence bond method, 34 135 Quantum chemistry, heat of chemisorption determination, 37 151-154 Quantum conversion, in chloroplasts, 14 1 Quantum mechanical simulations bond activation, 42 2, 84—107 Quasi-elastic neutron scattering benzene... 

B. O. Roos. The complete active space self-consistent field method and its apphca-tion in electronic structure calculations. In K. P. Lawley, editor, Ab Initio Methods in Quantum Chemistry. Part II, volume 69 of Adv. Chem. Phys., pages 399-446. John Wiley, Chichester, 1987. 

B. O.Roos, in Advances in Chemical Physysics (Ablnitio Methods in Quantum Chemistry— II), K. P. Lawley, Ed., Wiley, New York, 1987, Vol. 69, pp. 399-446. The Complete Active Space Self Consistent Field Method and Its Applications in Electronic Structure Calculations. 

Table III gives a complication of the ab initio molecular polarization propagator calculations that have appeared since the previous survey of the literature up through 1977 (Oddershede, 1978). Only calculations which go beyond RPA are included in Table III, and to get the full picture of the activity within the field of polarization propagator calculations Table III must be seen in conjunction with Table I. If we compare with Table A.I. of Oddershede (1978) and consider only calculations of the same kind, i.e. exclude atomic calculations and calculations using the CHF method from the previous review, it is evident that the number of polarization propagator calculations, like other kinds of electronic structure calculations, have increased substantially within the last decade and by now is becoming a useful tool in computational quantum chemistry.

These successes did not go unnoticed by industry. Several pharmaceutical companies (1963-1964) became interested in applications of it-electron theory to biochemistry. While it was admittedly premature, it was felt that quantum chemistry was both the wave of the future and the very matrix for rational drug design. Hiickel energies of cephalosporins could be correlated with their biological activities.While companies were applying some mathematical methods of correlation techniques in quantitative structure-activity relationships (QSAR), it was chiefly the Hiickel theory and various forms of semiempirical quantum mechanics that was using a large share of computer time on the IBM 7094 mainframe in 1966. 

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