Journal ArticleDOI
Applications of open-shell coupled cluster theory using an eigenvalue-independent partitioning technique: Approximate inclusion of triples in IP calculations
TLDR
In this article, the eigenvalue-independent partitioning (EIP) approach for the calculation of open-shell coupled cluster (CC) energy differences was used to compute the ionization potentials of HF and H 2 O using basis sets with and without polarization functions.About:
This article is published in Chemical Physics Letters.The article was published on 1989-10-20. It has received 74 citations till now. The article focuses on the topics: Coupled cluster & Ground state.read more
Citations
More filters
Journal ArticleDOI
Feasibility of Ionization-Mediated Pathway for Ultraviolet-Induced Melanin Damage.
TL;DR: The ionization energies of monomers, dimers, and few oligomers of eumelanin are calculated to estimate the threshold energy required for the ionization of euelsanin and it is found that this threshold is within the UV-B region for eumELanin.
Journal ArticleDOI
Quasidegenerate perturbation theory configuration interaction calculations of the core and valence photoelectron spectra of Ne and Ar
TL;DR: In this paper, the authors apply the sudden approximation for the calculation of the intensities of the photoelectron spectra of Ne and Ar to take into account the dynamical and non-dynamical correlation effects for both the valence and core ionizations, provided that static relaxation effects are explicitly taken into account through the use of SCF relaxed orbitals.
Journal ArticleDOI
Valence universal multireference coupled cluster calculations of the properties of indium in its ground and excited states
TL;DR: In this article, the effect of electron correlations on the ground and excited state properties is investigated using different levels of CC approximations and basis sets, and it is shown that a basis set with at least h-type of orbitals is ubiquitous to achieve converged results.
Journal ArticleDOI
Calculation of excitation energies using quasidegenerate variational perturbation theory and multireference-averaged coupled-pair functional theory
Mark A. Anderson,Robert J. Cave +1 more
TL;DR: In this paper, the ground and excited states of Be and SiH 2 from ab initio multireference singles and doubles configuration interaction, quasidegenerate variational perturbation theory, and multiireference-averaged coupled-pair functional theory calculations were compared with previously obtained full configuration interaction studies.
Journal ArticleDOI
Ring coupled-cluster doubles correction to geminal wavefunctions
Ágnes Szabados,Ádám Margócsy +1 more
TL;DR: A ring approximation in coupled-cluster theory is worked out at the multireference (MR) level in this article, where the underlying CC framework is based on generalised normal ordering and applies the corresponding generalised Wick's theorem.
References
More filters
Journal ArticleDOI
Gaussian Basis Functions for Use in Molecular Calculations. III. Contraction of (10s6p) Atomic Basis Sets for the First‐Row Atoms
TL;DR: In this paper, the effects of contraction on the energies and one-electron properties of the water and nitrogen molecules were investigated, and the authors obtained principles which can be used to predict optimal contraction schemes for other systems without the necessity of such exhaustive calculations.
Journal ArticleDOI
Gaussian‐Type Functions for Polyatomic Systems. II
Sigeru Huzinaga,Catalina Arnau +1 more
TL;DR: In this article, the use of a linear combination of Gaussian type orbitals (CGTO) instead of an individual Gaussian-type orbital (GTO) as a unit of basis functions for large-scale molecular calculations is discussed.
Journal ArticleDOI
Many-Body Perturbation Theory and Coupled Cluster Theory for Electron Correlation in Molecules
TL;DR: Manybody perturbation theory (MBPT) and coupled-cluster methcoder (CCM) were defined in this paper as a subset of the N-body problem.
Journal ArticleDOI
On the connectivity criteria in the open-shell coupled-cluster theory for general model spaces
TL;DR: In this article, the authors study the open-shell coupled-cluster theories and examine the current theoretical status regarding the existence or non-existence of a linked-clusters theorem, ensuring the connectedness of the cluster amplitudes and the effective Hamiltonian.