Density functional theory, and

L and W C Mackrodt 1994. Density Functional Theory and Interionic Potentials. Philosophical gazine B69-.871-878. 

Ah initio methods are applicable to the widest variety of property calculations. Many typical organic molecules can now be modeled with ah initio methods, such as Flartree-Fock, density functional theory, and Moller Plesset perturbation theory. Organic molecule calculations are made easier by the fact that most organic molecules have singlet spin ground states. Organics are the systems for which sophisticated properties, such as NMR chemical shifts and nonlinear optical properties, can be calculated most accurately. 

Chapter 6, Selecting an Appropriate Theoretical Method, discusses the model chemistry concept introduced in Chapter 1 in detail. It covers the strengths, computational cost and limitations of a variety of popular methods, beginning with semi-empirical models and continuing through Hartree-Fock, Density Functional Theory, and electron correlation methods. 

G. Vignale, in Current Density Functional Theory and Orbital Magnetism, Vol. 337 of Nato ASI Series, Series B, edited by E. K. U. Gross and R. M. Dreizler (Plenum Press, NewYork, 1995), p. 485. 

Fig. 4 Osmium clusters supported on MgO(OOl) a OssC/MgisOs and b OS5C at a surface point Vs defect site [33] these were represented by density functional theory, and the samples were characterized by EXAFS spectroscopy, transmission electron microscopy, and other techniques [15]...

If we except the Density Functional Theory and Coupled Clusters treatments (see, for example, reference [1] and references therein), the Configuration Interaction (Cl) and the Many-Body-Perturbation-Theory (MBPT) [2] approaches are the most widely-used methods to deal with the correlation problem in computational chemistry. The MBPT approach based on an HF-SCF (Hartree-Fock Self-Consistent Field) single reference taking RHF (Restricted Hartree-Fock) [3] or UHF (Unrestricted Hartree-Fock ) orbitals [4-6] has been particularly developed, at various order of perturbation n, leading to the widespread MPw or UMPw treatments when a Moller-Plesset (MP) partition of the electronic Hamiltonian is considered [7]. The implementation of such methods in various codes and the large distribution of some of them as black boxes make the MPn theories a common way for the non-specialist to tentatively include, with more or less relevancy, correlation effects in the calculations. 

Density functional theory and MP2 calculations on [Au2(hpp)2Cl2[ show that the HOMO is predominately hpp and chlorine-based with some Au-Au 5 character and that the LUMO has metal-to-ligand (M-L) and metal-to-metal (M-M) a character (approximately 50% hpp/chlorine, and 50% gold). DFT calculations on [Au4(hpp)4]... 

Fossgaard, O., Gropen, O., Eliav, E. and Saue, T. (2003) Bonding in the homologous series CsAu, CsAg, and CsCu studied at the 4-component density functional theory and coupled cluster levels. Journal of Chemical Physics, 119, 9355-9363. 

Vaara, J., Malkina, O.L., Stoll, H., Malkin, V.G. and Kaupp, M. (2001) Study of relativistic effects on nuclear shieldings using density-functional theory and spin-orbit pseudopotentials. Journal of Chemical Physics, 114, 61-71. 

The concept of the exchange-correlation hole is widely used in density functional theory and its most relevant properties are the subject of the following section. 

Encl[p] is the non-classical contribution to the electron-electron interaction containing all the effects of self-interaction correction, exchange and Coulomb correlation described previously. It will come as no surprise that finding explicit expressions for the yet unknown functionals, i. e. T[p] and Encl[p], represents the major challenge in density functional theory and a large fraction of this book will be devoted to that problem. 

What is obviously needed is a generally accepted recipe for how atomic states should be dealt with in approximate density functional theory and, indeed, a few empirical rules have been established in the past. Most importantly, due to the many ways atomic energies can be obtained, one should always explicitly specify how the calculations were performed to ensure reproducibility. From a technical point of view (after considerable discussions in the past among physicists) there is now a general consensus that open-shell atomic calculations should employ spin polarized densities, i. e. densities where not necessarily... 

Burke, K., Gross, E. K. U., 1998, A Guided Tour of Time-Dependent Density Functional Theory in Density Functionals Theory and Applications, Lecture Notes in Physics, Vol. 500, Joubert, D. (ed.), Springer, Heidelberg. 

Deng, L., Ziegler, T., 1997, Theoretical Study of the Oxidation of Alcohols to Aldehyde by d° Transition-Metal-Oxo Complexes Combined Approach Based on Density Functional Theory and die Intrinsic Reaction Coordinate Method , Organometallics, 16, 716. 

Grimme, S., Waletzke, M., 1999, A Combination of Kohn-Sham Density Functional Theory and Multi-Reference Configuration Interaction Methods , J. Chem. Phys., Ill, 5645. 

Guo, H., Sirois, S., Proynov, E. I., Salahub, D. R., 1997, Density Functional Theory and its Applications to Hydrogen-bonded Systems in Theoretical Treatments of Hydrogen Bonding, Hadzi, D. (ed.), Wiley, New York. 

Hobza, P., Spoiler, J., Reschel, T., 1995, Density Functional Theory and Molecular Clusters , J. Comput. Chem., 16, 1315. 

Kesyczynski, J. Goodman, L., Kwiatkowski, J. S., 1997, Density Functional Theory and Post-Hartree-Fock Studies on Molecular Structure and Harmonic Vibrational Spectrum of Formaldehyde , Theor. Chem. Acc., 97, 195. 

Schreckenbach, G., Ziegler, T., 1997a, Calculation of NMR Shielding Tensors Based on Density Functional Theory and a Scalar Relativistic Pauli-Type Hamiltonian. Application to Transition Metal Complexes , Int. J. 

Scott, A. P., Radom, L., 1996, Harmonic Vibrational Frequencies An Evaluation of Hartree-Fock, Moller-Plesset, Quadratic Configuration Interaction, Density Functional Theory, and Semiempirical Scale Factors , J. Phys. Chem., 100, 16502. 

Grimme S, Waletzke M (1999) A combination of KohnSham density functional theory and multireference configuration interaction methods. J Chem Phys 111 5645—5655... 

The crystal structures of raer-[lr(en)(enl I )C13]C1 1120 and mer-[Ir(en)(en )Cl3] show that the coordination geometry of Ir is almost identical in the two complexes, with the only difference being in the conformation of the unidentate en and enH+ groups.122 Density functional theory and ab initio calculations have been performed on the two complexes and the calculated confirmations agree well with the X-ray diffraction values.123 The enH+ ligand is stabilized via intramolecular N—H - - Cl hydrogen bonds. 

Wesolowski and Warshel197 introduced a DFT based approach in which all short-range terms in the effective Hamiltonian (Eq. 4.25) were derived entirely from density functional theory and were involved in the construction of the Fock matrix195 196. In this approach, the H croEnv is expressed using explicit functionals of the electron density ... 

Kwiatkowski, J. S., and J. Leszczynski. 1996. Molecular Structure and Vibrational IR Spectra of Cytosine and its thio and seleno Analogs by Density Functional Theory and Conventional ab initio Calculations. J. Phys. Chem. 100, 941. 

Hobza, R, J. Sponer, and T. Reschel. 1996. Density Functional Theory and Molecular Clusters. J. Comp. Chem. 17, 1315. 

Deng, L., V. Branchadell, and T. Ziegler. 1994. Potential Energy Surface of the Gas-Phase Sn2 Reactions X + CH2X = XCH3 + X- (X = F, Cl, Br, I) A Comparative Study by Density Functional Theory and ab initio Methods. 

Liechtenstein AI, Anisimov VI, Zaanen J (1995) Density-functional theory and strong interactions orbital ordering in Mott-Hubbard insulators. Phys Rev B 52(8) R5467... 

A. G. Zacarias, M. Castro, J. M. Tour, J. M. Seminario, Lowest Energy States of Small Pd Clusters Using Density Functional Theory and Standard ab Initio Methods. A Route to Understanding Metallic Nanoprobes, J. Rhys. Chem. A. 1999,103,7692-7700. 

Nalewajski, R. F. 2000. Coupling relations between molecular electronic and geometrical degrees of freedom in density functional theory and charge sensitivity analysis. Computers Chem. 24 243-257. 

Huang, Y., Zhong, A., Rong, C., Xiao, X., and Liu, S. 2008. Structure, spectroscopy, and reactivity properties of porphyrin pincers A conceptual density functional theory and time-dependent density functional theory study. J. Phys. Chem. A 112 305-311. 

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