Construction of tight-binding-like potentials on the basis of density-functional theory: Application to carbon

Structure and Stability of Molybdenum Sulfide Fullerenes

“…All calculations were performed using the DFTB method [20] with full geometry optimization. MD simulations (constant number, volume, and temperature (NVT) ensemble) were performed for the optimized structures.…”

Implementation of the SCC-DFTB Method for Hybrid QM/MM Simulations within the Amber Molecular Dynamics Package

“…The Kohn-Sham molecular orbitals ψ i are expanded in a minimal basis set of Slater-type confined atomic orbitals, i.e., as described by Eschrig and Bergert, 39 which is determined by solving the atomic Kohn-Sham problem in the presence of a confining potential. 38 These atomic orbitals (ϕ v ) are then used to calculate the Hamiltonian matrix elements as: (8) In Equation (8), is the Kohn-Sham eigenvalue for orbital ϕ μ in the unconfined atom, and three-center terms have been neglected. The Hamiltonian and overlap matrix elements are then pre-calculated in this two-center approximation for interatomic distances on a relevant scale and tabulated, 25,38 and matrix elements at arbitrary distances can be obtained by interpolation from the tables.…”

Parameter Calibration of Transition-Metal Elements for the Spin-Polarized Self-Consistent-Charge Density-Functional Tight-Binding (DFTB) Method: Sc, Ti, Fe, Co, and Ni

“…An alternative approach to perform calculations for such large systems is an approximate density functional technique called the density functional tight-binding (DFTB) method. 10,11 This method has been applied to calculating energies, geometries and spectra of organic and inorganic molecules; [10][11][12][13][14] The accuracy for molecular geometries is comparable to that of DFT-GGA methods, while reaction energies and vibrational frequencies are slightly less accurate. Recently, a special parameterization for vibrational frequencies has shown that DFTB can approach the DFT accuracy, 15 while heats of formation are still slightly less accurate than those determined at recently optimized MNDO approaches.…”

“…The SCF procedure minimizes the dependence of the results on the choice of the zero-order initial density, and substantially increases the transferability of the parameters in comparison with the non-self-consistent-charge approach. 11 In addition, the spin-polarized version of DFTB distinguishes different spin distributions (whereas spin-unpolarized DFTB depends only on the total electron density) and can qualitatively describe different spin states, a fact that is essential for transition metal elements. All the needed one-and two-center integrals are pre-computed for a large number of grid points, and in practical calculations, the actual values of integrals are obtained by a suitable interpolation scheme, usually a cubic spline function fitting.…”