Tight-Binding Configuration Interaction (TBCI): A Noniterative Approach to Incorporating Electrostatics into Tight Binding

Abstract

We present a new electronic structure approximation called Tight Binding Configuration Interaction. It uses a tight-binding Hamiltonian to obtain orbitals that are used in a configuration interaction calculation that includes explicit charge interactions. This new method is better capable of predicting energies, ionization potentials, and fragmentation charges than the Wolfsberg-Helmholz Tight-Binding and Many-Body Tight-Binding models reported earlier (Staszewska, G.; Staszewski, P.; Schultz, N. E.; Truhlar, D. Phys. Rev. B 2005, 71, 045423). The method is illustrated for clusters and nanoparticles containing aluminum.

What Makes the Photocatalytic CO2 Reduction on N-Doped Ta2O5 Efficient: Insights from Nonadiabatic Molecular Dynamics

“…Keeping in mind that such calculations must be done for many configurations along the MD trajectory, and that NAC matrices must be computed as well, the computational expenses become unfeasible for standard ab initio or DFT methods. At the same time, the tight-binding theories, including EHT, are well-known for capturing essential physics, − ,,− which makes them reliable and transparent for qualitative analysis of chemical phenomena.…”

“…Although EHT is a well-defined tight-binding method, it lacks explicit electrostatic effects . The effects can be included in a more elaborate self-consistent charge version − or using a configuration-interaction approach, but the costs would increase by at least an order of magnitude due to the need for self-consistency iterations or multiple configurations, respectively. Therefore, in the present work we choose to develop an effective parametrization that would capture the shift of the CB minimum level in N-doped Ta 2 O 5 , placing this level above the acceptor levels of the Ru complexes.…”

Polarized Molecular Orbital Model Chemistry 3. The PMO Method Extended to Organic Chemistry

“…In the PMO2 method, 82 independent parameters are optimized for compounds composed of H, C, and O. We determine the “best” parameter set using a GA. , We note that GA algorithms have also been used successfully in parameter optimization in the development of previous semiempirical methods. − The main advantage of using a GA algorithm is the ability to explore a high-dimensional space without being trapped in a local shallow minimum. In the GA, random numbers are used in creating each new generation of the parameters, and the parameters are evolved from an initial parameter set within user-specified ranges to find their optimum values.…”

Nonadiabatic Molecular Dynamics with Tight-Binding Fragment Molecular Orbitals

“…As with many semiempirical theories, essential correlation and electrostatic effects can be implicitly included via a parametrization tuned to a specific system. Further extensions to incorporate charge-transfer effects within the tight-binding formulation can be envisioned along the lines of the tight-binding configuration interaction (TB-CI) method developed in the Truhlar group …”

“…Further extensions to incorporate charge-transfer effects within the tight-binding formulation can be envisioned along the lines of the tight-binding configuration interaction (TB-CI) method developed in the Truhlar group. 85 The approximations above have been discussed keeping only the nonorthogonal basis states in mind, |ψ⟩. In the basis of the Loẅdin-orthogonalized states, |ψ̃L⟩, the corresponding electronic Hamiltonian is obtained by the similarity transformation:…”