Density functionals molecular properties

We have used transferable atom equivalent (TAE) descriptors [116,117] that encode the distributions of electron density based molecular properties, such as kinetic energy densities, local average ionization potentials, Fukui functions, electron density gradients, and second derivatives as well as the density itself. In addition autocorrelation descriptors (RAD) were used and represent the molecular geometry characteristics of the molecules, while they are also canonical and independent of 3D coordinates. The 2D descriptors alone or in combination with the latter 3D descriptors were calculated for 26 data sets collated by us from numerous publications. These data sets encompass various ADME/TOX-related enzymes, transporters, and ion channels as... 

Historically, solvents have been designed to maximize technical performance and minimize cost. To achieve a high efficacy of function, molecular properties of solvents e.g. polarity, solubility, viseosity, vapour pressure, density and... 

The electronic and transport properties of an amorphous graphitic carbon model constructed by Townsend et al, [112,114] were studied by first-principles calculations in the local-density approximation. Semiempirical density-functional molecular dynamics (DF-MD) was used to simulate the experiments, e.g., neutron diffraction, inelastic neutron scattering, and NMR, to determine the structure of the system in order to achieve a fundamental understanding of structure-related properties on the molecular level of chemical bonding. The total energy of the system... 

Using ab initio, density-functional, molecular-dynamics calculations on the Nuat clusters, Zorriasatein et al studied also the thermodynamic properties of those. As discussed above for the study of Eryiirek and Giiven, also Zorriasatein et al. found that the melting temperature depends in a highly non-trivial way on the cluster size. 

Many molecular properties can be related directly to the wave function or total electron density. Some examples are dipole moments, polarizability, the electrostatic potential, and charges on atoms. 

In 1985 Car and Parrinello invented a method [111-113] in which molecular dynamics (MD) methods are combined with first-principles computations such that the interatomic forces due to the electronic degrees of freedom are computed by density functional theory [114-116] and the statistical properties by the MD method. This method and related ab initio simulations have been successfully applied to carbon [117], silicon [118-120], copper [121], surface reconstruction [122-128], atomic clusters [129-133], molecular crystals [134], the epitaxial growth of metals [135-140], and many other systems for a review see Ref. 113. 

Ab initio molecular orbital theory is concerned with predicting the properties of atomic and molecular systems. It is based upon the fundamental laws of quantum mechanics and uses a variety of mathematical transformation and approximation techniques to solve the fundamental equations. This appendix provides an introductory overview of the theory underlying ab initio electronic structure methods. The final section provides a similar overview of the theory underlying Density Functional Theory methods. 

Extensive quantum chemical calculations have been reported for sulfur-rich compounds in the past two decades. These calculations were used to investigate molecular structures and spectroscopic properties, as well as to understand the nature chemical bonding and reaction mechanism. Many high-level ab initio calculations were used for interpretation of experimental data and for providing accurate predictions of molecular structures and thermochemical data where no reliable experimental values are available. In recent years, density functional calculations have been extensively tested and used on many first- and second-row compounds. These proven DFT methods look promising for larger systems because for their computational efficiency. 

Chattaraj PK, Parr RG (1993) Density Functional Theory of Chemical Hardness. 80 11-26 Cheh AM, Neilands JP (1976) The j -Aminoevulinate Dehydratases Molecular and Environmental Properties. 29 123-169 Chimiak A, Neilands JB (1984) Lysine Analogues of Siderophores. 58 89-96 Christensen JJ, see Izatt RM (1973) 16 161-189... 

The molecular interpretation of major topics in catalytic kinetics will be highlighted based on insights on the properties of transition-state intermediates as deduced from computational chemical density functional theory (DFT) calculations. 

These limitations, most urgently felt in solid state theory, have stimulated the search for alternative approaches to the many-body problem of an interacting electron system as found in solids, surfaces, interfaces, and molecular systems. Today, local density functional (LDF) theory (3-4) and its generalization to spin polarized systems (5-6) are known to provide accurate descriptions of the electronic and magnetic structures as well as other ground state properties such as bond distances and force constants in bulk solids and surfaces. 

Thus, the electron density already provides all the ingredients that we identified as being necessary for setting up the system specific Hamiltonian and it seems at least very plausible that in fact p( ) suffices for a complete determination of all molecular properties (of course, this does not relieve us from the task of actually solving the corresponding Schrodinger equation and all the difficulties related to this). As noted by Handy, 1994, these very simple and beautifully intuitive arguments in favor of density functional theory are attributed to E. B. Wilson. So the answer to the question posed in the caption to this section is certainly a loud and clear Yes . 

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