Structural and electronic properties oftrans-polysilene (SiH)x: Many-body perturbation theory versus density-functional methods

1995 ◽  
Vol 52 (3) ◽  
pp. 1674-1677 ◽  
Author(s):  
Sándor Suhai
Keyword(s):  
Perturbation Theory ◽  
Electronic Properties ◽  
Density Functional ◽  
Many Body ◽  
Density Functional Methods ◽  
Functional Methods ◽  
Structural And Electronic Properties ◽  
Theory Versus ◽  
Many Body Perturbation Theory

scholarly journals Optical and Electronic Properties of Organic NIR-II Fluorophores by Time-Dependent Density Functional Theory and Many-Body Perturbation Theory: GW-BSE Approaches

Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2293
Author(s):  
Nguyet N. T. Pham ◽  
Seong Hun Han ◽  
Jong S. Park ◽  
Seung Geol Lee
Keyword(s):  
Density Functional Theory ◽  
Perturbation Theory ◽  
Electronic Properties ◽  
Density Functional ◽  
Time Dependent ◽  
Many Body ◽  
Functional Theory ◽  
Optical And Electronic Properties ◽  
Many Body Perturbation Theory ◽  
Dependent Density

Organic-molecule fluorophores with emission wavelengths in the second near-infrared window (NIR-II, 1000–1700 nm) have attracted substantial attention in the life sciences and in biomedical applications because of their excellent resolution and sensitivity. However, adequate theoretical levels to provide efficient and accurate estimations of the optical and electronic properties of organic NIR-II fluorophores are lacking. The standard approach for these calculations has been time-dependent density functional theory (TDDFT). However, the size and large excitonic energies of these compounds pose challenges with respect to computational cost and time. In this study, we used the GW approximation combined with the Bethe-Salpeter equation (GW-BSE) implemented in many-body perturbation theory approaches based on density functional theory. This method was used to perform calculations of the excited states of two NIR molecular fluorophores (BTC980 and BTC1070), going beyond TDDFT. In this study, the optical absorption spectra and frontier molecular orbitals of these compounds were compared using TDDFT and GW-BSE calculations. The GW-BSE estimates showed excellent agreement with previously reported experimental results.

scholarly journals Many-Body Perturbation Theory Using the Density-Functional Concept: Beyond theGWApproximation

2005 ◽  
Vol 94 (18) ◽  
Author(s):  
Fabien Bruneval ◽  
Francesco Sottile ◽  
Valerio Olevano ◽  
Rodolfo Del Sole ◽  
Lucia Reining
Keyword(s):  
Perturbation Theory ◽  
Density Functional ◽  
Many Body ◽  
Many Body Perturbation Theory ◽  
Functional Concept

scholarly journals Capturing excitonic and polaronic effects in lead iodide perovskites from many-body perturbation theory

2021 ◽  
Author(s):  
Pooja Basera ◽  
Arunima Singh ◽  
Deepika Gill ◽  
Saswata Bhattacharya
Keyword(s):  
Optical Properties ◽  
Perturbation Theory ◽  
Binding Energy ◽  
Electronic Properties ◽  
Effective Mass ◽  
Exciton Binding Energy ◽  
Many Body ◽  
Energy Materials ◽  
Lead Iodide ◽  
Many Body Perturbation Theory

Lead iodide perovskites have attracted considerable interest as promising energy-materials. However, till date, several key electronic properties such as optical properties, effective mass, exciton binding energy and the radiative exciton...

scholarly journals Psi4 1.4: Open-Source Software for High-Throughput Quantum Chemistry

2020 ◽  
Author(s):  
Daniel Smith ◽  
Lori Burns ◽  
Andrew Simmonett ◽  
Robert Parrish ◽  
Matthew Schieber ◽  
...  
Keyword(s):  
Perturbation Theory ◽  
Quantum Chemistry ◽  
Open Source ◽  
Density Functional ◽  
Many Body ◽  
Hartree Fock ◽  
Large Numbers ◽  
Many Body Perturbation Theory ◽  
Infrastructure Project ◽  
Job Specification

<div> <div> <div> <p>Psi4 is a free and open-source ab initio electronic structure program providing Hartree–Fock, density functional theory, many-body perturbation theory, configuration interaction, density cumulant theory, symmetry-adapted perturbation theory, and coupled-cluster theory. Most of the methods are quite efficient thanks to density fitting and multi-core parallelism. The program is a hybrid of C++ and Python, and calculations may be run with very simple text files or using the Python API, facilitating post-processing and complex workflows; method developers also have access to most of Psi4’s core functionality via Python. Job specification may be passed using The Molecular Sciences Software Institute (MolSSI) QCSchema data format, facilitating interoperability. A rewrite of our top-level computation driver, and concomitant adoption of the MolSSI QCArchive Infrastructure project, make the latest version of Psi4 well suited to distributed computation of large numbers of independent tasks. The project has fostered the development of independent software components that may be reused in other quantum chemistry programs. </p> </div> </div> </div>

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