A time-dependent semiempirical approach to determining excited states

Bartell, Lizette A.; Wall, Michael R.; Neuhauser, Daniel

doi:10.1063/1.3453683

Cited by 21 publications

(23 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Semi-empirical methods are excluded from the discussion here, and the reader is referred to existing information in this field [1,2]. Nonetheless, it is important to note that multireference approaches based on semi-empirical model Hamiltonians, such as AM1/MRCI or OM2/MRCI, represent promising approaches to treat excited-state problems with substantial multireference character [3][4][5].…”

Section: Existing Excited-state Methods For Medium-sized and Large Momentioning

confidence: 99%

See 1 more Smart Citation

The Art of Choosing the Right Quantum Chemical Excited‐State Method for Large Molecular Systems

Harbach¹,

Dreuw²

2011

Modeling of Molecular Properties

View full text Add to dashboard Cite

Section: Existing Excited-state Methods For Medium-sized and Large Momentioning

confidence: 99%

“…ADC(2)-x is currently the computationally most efficient ab initio method including doubly excited states in first-order perturbation theory. Efficient ADC (2) codes are at present available in Turbomole [12], where the ADC(2)-s variant is implemented [18], and in Q-Chem where both ADC(2) variants are available.…”

Section: Wavefunction-based Ab Initio Methodsmentioning

confidence: 99%

The Art of Choosing the Right Quantum Chemical Excited‐State Method for Large Molecular Systems

Harbach¹,

Dreuw²

2011

Modeling of Molecular Properties

View full text Add to dashboard Cite

“…24 Therefore, the memory usage scales as O(N 2 ) for storing the Fock/Kohn-Sham and density matrices, as well as in diagonalization routines. (14) is considered in the active component. (7) is different from the linear-response formalism of the TDDFT.…”

Section: B Dynamically Active Space and Incremental Fock/kohn-sham Bmentioning

confidence: 99%

“…13,14 In the weak perturbation regime, TDHF/TDDFT can be truncated to include only first order corrections, an approach embodied by the linear response equation. While there are a number of noteworthy recent works that consider all-electron dynamics for large systems, such as pentacene and C 60 , they were performed using a semiempirical Hamiltonian such as TDPPP and TDPM3.…”

Section: Introductionmentioning

confidence: 99%

Efficient first-principles electronic dynamics

Liang

Chapman

2011

The Journal of Chemical Physics

View full text Add to dashboard Cite

An efficient first-principles electronic dynamics method is introduced in this article. The approach we put forth relies on incrementally constructing a time-dependent Fock∕Kohn-Sham matrix using active space density screening method that reduces the cost of computing two-electron repulsion integrals. An adaptive stepsize control algorithm is developed to optimize the efficiency of the electronic dynamics while maintaining good energy conservation. A selected set of model dipolar push-pull chromophore molecules are tested and compared with the conventional method of direct formation of the Fock∕Kohn-Sham matrix. While both methods considered herein take on identical dynamical simulation pathways for the molecules tested, the active space density screening algorithm becomes much more computationally efficient. The adaptive stepsize control algorithm, when used in conjunction with the dynamically active space method, yields a factor of ∼3 speed-up in computational cost as observed in electronic dynamics using the time dependent density functional theory. The total computational cost scales nearly linear with increasing size of the molecular system.

show abstract

“…Other time-dependent semi-empirical approaches have been developed [7][8][9]. The low lying excited states of large systems have been studied with pseudo spectral TDDFT [10,11] which leads to a significant speedup in the calculations.…”

Section: Introductionmentioning

confidence: 99%

Assessment of time-dependent density functional theory with the restricted excitation space approximation for excited state calculations of large systems

2018

View full text Add to dashboard Cite

The restricted excitation subspace approximation is explored as a basis to reduce the memory storage required in linear response time-dependent density functional theory (TDDFT) calculations within the Tamm-Dancoff approximation. It is shown that excluding the core orbitals and up to 70% of the virtual orbitals in the construction of the excitation subspace does not result in significant changes in computed UV/vis spectra for large molecules. The reduced size of the excitation subspace greatly reduces the size of the subspace vectors that need to be stored when using the Davidson procedure to determine the eigenvalues of the TDDFT equations. Furthermore, additional screening of the twoelectron integrals in combination with a reduction in the size of the numerical integration grid used in the TDDFT calculation leads to significant computational savings. The use of these approximations represents a simple approach to extend TDDFT to the study of large systems and make the calculations increasingly tractable using modest computing resources.

show abstract

A time-dependent semiempirical approach to determining excited states

Cited by 21 publications

References 35 publications

The Art of Choosing the Right Quantum Chemical Excited‐State Method for Large Molecular Systems

The Art of Choosing the Right Quantum Chemical Excited‐State Method for Large Molecular Systems

Efficient first-principles electronic dynamics

Assessment of time-dependent density functional theory with the restricted excitation space approximation for excited state calculations of large systems

Contact Info

Product

Resources

About