Multiconfigurational Hartree–Fock response functions

Jørgensen, Poul; Swanstrøm, Peter; Yeager, Danny L.; Olsen, Jeppe

doi:10.1002/qua.560230319

Cited by 33 publications

(28 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Although double excitations could be included in extended or higher-order RPA formalisms [57], these methods did not receive wide attention. Instead, LR has been applied to correlated ground states, including MultiConfiguration Self Consistent Field (MCSCF) [58], and Coupled Cluster (CC) [59][60][61] methods.…”

Section: Tddft and A Posteriori Tammdancoff Approximation To The Secomentioning

confidence: 99%

Theory and computations of two-photon absorbing photochromic chromophores

Masunov

Михайлов

2010

Eur. J. Chem.

View full text Add to dashboard Cite

KEYWORDSExponential growth in information technology generates ever increasing amounts of data, making recording density of the storage media crucially important. Two-photon absorption was proposed as a basis for high-density multi-layer technology for optical memory and logic devices. This technology suggests to use polymers, doped with photochromic compounds that undergo a reversible photoinduced isomerization, or photoswitching. In this review we consider recent theoretical works and benchmarking studies of the DFT-based methods, capable to predict two-photon absorption (2PA) and photochemical activity, Next we review the applications of these methods to design a prototype molecule that combines the photonmode recording property of photochromic compounds with large 2PA cross-section. We conclude that a posteriori Tamm-Dancoff approximation to the second order CEO approach in Density Functional Theory is the powerful tool for both quantitative predictions and qualitative understanding of the excited state processes in photophysics and photochemistry. We also emphasize general principles for the rational design of a two-photon operated photoswitch.TDDFT Organic photochemistry Photocyclization Photoinduced reactions Two-photon absorption State-to-state transition dipoles

show abstract

Section: Tddft and A Posteriori Tammdancoff Approximation To The Secomentioning

confidence: 99%

Theory and computations of two-photon absorbing photochromic chromophores

Masunov

Михайлов

2010

Eur. J. Chem.

View full text Add to dashboard Cite

show abstract

“…Furthermore, trust region schemes [44] can be likewise straightforwardly implemented with the formulas being exactly the same (with modifications specified in the previous paragraph) as have been developed for MCSCF with real Hermitian Hamiltonians. These trust region methods are used to reliably bring an MCSCF calculation into the local region where quadratic convergence can be extremely beneficial.…”

Section: An Example: a Quadratically Convergent Bivariational Complexmentioning

confidence: 99%

“…Complex-scaled quadratically convergent self-consistent field (SCF) can also be performed straightforwardly by limiting the number of spinorbital determinants to one. Use of trust region methods developed for MCSCF optimization with real Hermitian Hamiltonians [44] to move a calculation into the "local" region and guarantee convergence for the lowest energy state of each symmetry will contribute further to rapid and reliable convergence.…”

Section: With This Scaling H † () ϭ H*() H()mentioning

confidence: 99%

“…The ease of application is demonstrated by deriving modified equations for a quadratically convergent procedure developed previously for multiconfigurational self-consistent field methods (MCSCF) for real Hermitian Hamiltonians [41][42][43][44] to be applied to complex-scaled Hamiltonians with very simple modifications outlined in the third section. Complex-scaled quadratically convergent self-consistent field (SCF) can also be performed straightforwardly by limiting the number of spinorbital determinants to one.…”

Section: With This Scaling H † () ϭ H*() H()mentioning

confidence: 99%

See 1 more Smart Citation

Algebraic modifications to second quantization for non‐Hermitian complex scaled hamiltonians with application to a quadratically convergent multiconfigurational self‐consistent field method

Yeager

Mishra

2005

Int J of Quantum Chemistry

Self Cite

View full text Add to dashboard Cite

ABSTRACT:The algebraic structure for creation and annihilation operators defined on orthogonal orbitals is generalized to permit easy development of bound-state techniques involving the use of non-Hermitian Hamiltonians arising from the use of complex-scaling or complex-absorbing potentials in the treatment of electron scattering resonances. These extensions are made possible by an orthogonal transformation of complex biorthogonal orbitals and states as opposed to the customary unitary transformation of real orthogonal orbitals and states and preserve all other formal and numerical simplicities of existing bound-state methods. The ease of application is demonstrated by deriving the modified equations for implementation of a quadratically convergent multiconfigurational self-consistent field (MCSCF) method for complexscaled Hamiltonians but the generalizations are equally applicable for the extension of other techniques such as single and multireference coupled cluster (CC) and many-body perturbation theory (MBPT) methods for their use in the treatment of resonances. This extends the domain of applicability of MCSCF, CC, MBPT, and methods based on MCSCF states to an accurate treatment of resonances while still using L 2 real basis sets. Modification of all other bound-state methods and codes should be similarly straightforward.

show abstract

“…Note that the same Hessian is used for all perturbations. These are the coupled multiconfigurational HartreeFock (CMCHF) equations given elsewhere [30,35,36]. Considering the potentially huge dimensions of the Hessian matrix, the working CMCHF equations are better represented by These equations are still not suitable for large-scale calculations, as the configuration parts of the gradient and the Hessian are written in terms of the (unknown) eigenvectors of the N-dimensional orthogonal complement of the reference state.…”

Section: E~= E ; + T K " + O (~)mentioning

confidence: 99%

A second‐quantization approach to the analytical evaluation of response properties for perturbation‐dependent basis sets

Helgaker

Almlöf

1984

Int J of Quantum Chemistry

View full text Add to dashboard Cite

A general theory for response properties is presented which is applicable to perturbations affecting the molecular basis set, notably nuclear derivatives. A perturbation-independent Fock space is introduced, and the necessary reorthonormalization of a truncated basis set after a perturbation is explicitly incorporated in the Hamiltonian. Explicit formulas for MCSCF first-and second-order properties are presented, and some computational aspects are briefly discussed. A brief comparison with previous results is given.

show abstract

Multiconfigurational Hartree–Fock response functions

Cited by 33 publications

References 14 publications

Theory and computations of two-photon absorbing photochromic chromophores

Theory and computations of two-photon absorbing photochromic chromophores

Algebraic modifications to second quantization for non‐Hermitian complex scaled hamiltonians with application to a quadratically convergent multiconfigurational self‐consistent field method

A second‐quantization approach to the analytical evaluation of response properties for perturbation‐dependent basis sets

Contact Info

Product

Resources

About