Efficient calculations of a large number of highly excited states for multiconfigurational wavefunctions.

08:00 EDT 2nd April 2019 | BioPortfolio

Summary of "Efficient calculations of a large number of highly excited states for multiconfigurational wavefunctions."

Electronically excited states play important roles in many chemical reactions and spectroscopic techniques. In quantum chemistry, a common technique to solve excited states is the multiroot Davidson algorithm, but it is not designed for processes like X-ray spectroscopy that involves hundreds of highly excited states. We show how the use of a restricted active space wavefunction together with a projection operator to remove low-lying electronic states offers an efficient way to reach single and double-core-hole states. Additionally, several improvements to the stability and efficiency of the configuration interaction (CI) algorithm for a large number of states are suggested. When applied to a series of transition metal complexes the new CI algorithm does not only resolve divergence issues but also leads to typical reduction in computational time by 70%, with the largest savings for small molecules and large active spaces. Together, the projection operator and the improved CI algorithm now make it possible to simulate a wide range of single- and two-photon spectroscopies. © 2019 Wiley Periodicals, Inc.


Journal Details

This article was published in the following journal.

Name: Journal of computational chemistry
ISSN: 1096-987X


DeepDyve research library

PubMed Articles [25157 Associated PubMed Articles listed on BioPortfolio]

Double-buffered, heterogeneous CPU + GPU integral digestion algorithm for single-excitation calculations involving a large number of excited states.

The most widely used quantum-chemical models for excited states are single-excitation theories, a category that includes configuration interaction with single substitutions, time-dependent density fun...

Symmetries and Many-Body Excitations with Neural-Network Quantum States.

Artificial neural networks have been recently introduced as a general ansatz to represent many-body wave functions. In conjunction with variational Monte Carlo calculations, this ansatz has been appl...

Ground-State Pd Anions React with H Much Faster than the Excited Pd Anions.

Recent advances in experimental techniques have made it relatively easy to prepare reactant cations in well-defined states of electronic excitation. Extensive studies on the role of excited states in ...

Development of large-scale excited-state calculations based on the divide-and-conquer time-dependent density functional tight-binding method.

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 ...

Evidence for Coexisting Shapes through Lifetime Measurements in ^{98}Zr.

The lifetimes of the first excited 2^{+}, 4^{+}, and 6^{+} states in ^{98}Zr were measured with the recoil-distance Doppler shift method in an experiment performed at GANIL. Excited states in ^{98}Zr ...

Clinical Trials [6627 Associated Clinical Trials listed on BioPortfolio]

DE-CT in Lung Cancer Proton Therapy

Dose distribution calculations for proton therapy are more accurate when based on DE-CT than on SE-CT. It is however unclear what the quantitative benefit of repeated DE-CT calculations is...

Hemodynamic Correlates of Distinct Hypnotic States

The investigation will assess the brain activation connectivity patterns associated with hypnosis and possible hypnotic sub-states by means of functional magnetic resonance imaging (fMRI)....

FCM Analysis GR in Steroid-Treatment Patients

Monitoring the GR with a GR-MoAb and FITC-Dex probes by FCM would be useful and convenient in determination GR before the steroid treatment in clinical, especially in steroid resistant sta...

Safety and Immune Response to a Multi-component Immune Based Therapy (MKC1106-PP) for Patients With Advanced Cancer.

The present clinical trial is a dose comparison of a multi-component active immunotherapy designed to stimulate an immune reaction to specific tumor associated antigens which are highly ex...

Study of T Lymphocytes in Patients With Horton Disease

Giant-cell arteritis (GCA) is the most frequent vasculitis after 50 years. Corticosteroid therapy is the reference treatment for GCA. This treatment is highly effective but must be maintai...

Medical and Biotech [MESH] Definitions

Math calculations done for preparing appropriate doses of medicines, taking into account conversions of WEIGHTS AND MEASURES. Mistakes are one of the sources of MEDICATION ERRORS.

A highly chlorinated polycyclic hydrocarbon insecticide whose large number of chlorine atoms makes it resistant to degradation. It has been shown to be toxic to mammals and causes abnormal cellular changes in laboratory animals.

A highly-sensitive (in the picomolar range, which is 10,000-fold more sensitive than conventional electrophoresis) and efficient technique that allows separation of PROTEINS; NUCLEIC ACIDS; and CARBOHYDRATES. (Segen, Dictionary of Modern Medicine, 1992)

A family of highly acidic calcium-binding proteins found in large concentration in the brain and believed to be glial in origin. They are also found in other organs in the body. They have in common the EF-hand motif (EF HAND MOTIFS) found on a number of calcium binding proteins. The name of this family derives from the property of being soluble in a 100% saturated ammonium sulfate solution.

1861-1865 conflict between the Union (Northern states) and the 11 Southern states that seceded and were organized as the Confederate States of America.

Quick Search


DeepDyve research library

Relevant Topic

Radiology is the branch of medicine that studies imaging of the body; X-ray (basic, angiography, barium swallows), ultrasound, MRI, CT and PET. These imaging techniques can be used to diagnose, but also to treat a range of conditions, by allowing visuali...

Searches Linking to this Article