Development of Large-Scale Excited-State Calculations Based on the Divide-and-Conquer Time-Dependent Density Functional Tight-Binding Method

Abstract

In this study, the divide-and-conquer (DC) method was extended to time-dependent density functional tight-binding (TDDFTB) theory to enable excited-state calculations of large systems and is denoted by DC-TDDFTB. The efficient diagonalization algorithms of TDDFTB and DC-TDDFTB methods were implemented into our in-house program. Test calculations of polyethylene aldehyde and p-coumaric acid, a pigment in photoactive yellow protein, in water demonstrate the high accuracy and efficiency of the developed DC-TDDFTB method. Furthermore, the (TD)-DFTB metadynamics simulations of acridinium in the ground and excited states give reasonable pK a values compared with the corresponding experimental values.

GPU‐Accelerated Large‐Scale Excited‐State Simulation Based on Divide‐and‐Conquer Time‐Dependent Density‐Functional Tight‐Binding

“…In a previous study, we proposed the excited‐state DC‐TDDFTB theory and here it will be briefly summarized. In the DC method, the system under consideration is spatially partitioned into disjoint subsystems, where a set of atomic orbitals (AOs) in a subsystem, s , is represented as S ( s ): The union of S ( s ) becomes a set of AOs in the entire system represented as T : The disjoint subsystem is known as the central region.…”

“…Recently, quantum mechanical molecular dynamics (QM‐MD) simulations for tens of thousands atoms in the ground states have been accomplished by applying the DC method to the density‐functional tight‐binding (DFTB) method, which is an approximation to DFT with the concept of adopting up to two‐center terms for parameterized integrals and repulsive potential. Furthermore, the combination of the DC method and the time‐dependent (TD) DFTB method was also examined …”

Energy-Based Automatic Determination of Buffer Region in the Divide-and-Conquer Second-Order Møller-Plesset Perturbation Theory

“…[23,24] Yang and coworkers introduced a linear-scaling approach called the divide-andconquer (DC) method. [25,26] The DC method has been applied to the HF or DFT selfconsistent field (SCF), [25,27] density-functional tight-binding, [28][29][30][31] and post-HF (MP2 [32][33][34][35] or CC [36][37][38] ) energy calculations as well as the SCF [39] and MP2 [40] energy gradient calculations. For treating static electron correlation in large-scale systems, the DC method has also been combined with the Hartree-Fock-Bogoliubov method [41] and the thermallyassisted occupation (finite temperature) scheme.…”

Spin‐flip approach within time‐dependent density functional tight‐binding method: Theory and applications

“…A large number of extensions to the standard DFTB framework have been developed, such as the linear‐response time‐dependent (TD) approach, long‐range correction (LC), various schemes for noncovalent interactions, and self‐interaction correction . Recently, quantum chemical simulations of systems with more than 1,000 atoms were accomplished by utilizing multilayer and linear‐scaling methods . Also, our original linear‐scaling program for the massive parallel architecture, DCDFTBMD, was successful in describing various chemical phenomena in complex systems .…”