Density functional tight-binding DFTB

One such model that has promise is density functional tight-binding (DFTB) theory. In DFTB, we begin by expressing the energy associated with a reference density po(r) as... 

We have employed a density-functional tight-binding (DFTB) scheme for the calculation of the total energy and several properties of a wide range of MOF crystal structures. Periodic boundary conditions (PBC) have been used to represent the infinite framework of the solid state. Lattice parameters and MOF structures have been fully optimized. The number of k points was determined by reaching convergence with respect to the total energy. 

Based on the previous implementation of the density functional tight-binding (DFTB) method in ALLCHEM, a hybrid DFT/DFTB method is currently under development. In the future this will be coupled to a molecular mechanics environment. 

In our subsequent studies on Aujv clusters we included a treatment of the electronic orbitals. For the calculation of the total energy of a given structure we used the parameterized density-functional tight-binding (DFTB) method of Seifert et al. For the determination of the structure of the lowest total energy we combined this method with genetic algorithms. We shall briefly discuss the results of the most extensive of those studies where Aujv clusters with N up to 58 were considered. ... 

The molecular geometry of swainsonine (378) has been modeled with the aid of the density functional tight-binding (DFTB) technique as a prelude to computing its intercalation into DNA. The calculations, the first of their kind, showed the alkaloid to be a good electron acceptor toward... 

Density Functional Tight-Binding (DFTB) Method... 

It is worth noting that when advanced QM methods cannot be used for the calculations, as in the case of large chromophores interacting with many water molecules, one possible approach is to use semiempirical models. For example, we showed that reliable solvatochromic shifts can be obtained using the Density Functional Tight Binding (DFTB) method [164, 165] in conjunction with PCM (see Table 17.1). 

MULTI-SCALE QM/MM METHODS WITH SELF-CONSISTENT-CHARGE DENSITY-FUNCTIONAL-TIGHT-BINDING (SCC-DFTB)... 

DFTB Density functional tight-binding theory... 

SCC-DFTB Self-consistent charge density functional tight-binding theory SCF Self-consistent field... 

Cui Q, M Elstner, E Kaxiras, T Frauenheim, M Karplus (2001) A QM/MM implementation of the self-consistent charge density functional tight binding (SCC-DFTB) method. J. Phys. Chem. B 105 (2) 569-585... 

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