scholarly journals Beyond theGWapproximation: A second-order screened exchange correction

2015 ◽  
Vol 92 (8) ◽  
Author(s):  
Xinguo Ren ◽  
Noa Marom ◽  
Fabio Caruso ◽  
Matthias Scheffler ◽  
Patrick Rinke
Keyword(s):  
Second Order ◽  
Exchange Correction ◽  
Screened Exchange

Short-range second order screened exchange correction to RPA correlation energies

2017 ◽  
Vol 147 (20) ◽  
pp. 204107 ◽  
Author(s):  
Matthias Beuerle ◽  
Christian Ochsenfeld
Keyword(s):  
Short Range ◽  
Second Order ◽  
Exchange Correction ◽  
Screened Exchange

Reducing the Many-Electron Self-Interaction Error in the Second-Order Screened Exchange Method

2019 ◽  
Vol 15 (12) ◽  
pp. 6607-6616 ◽  
Author(s):  
Pál D. Mezei ◽  
Adrienn Ruzsinszky ◽  
Mihály Kállay
Keyword(s):  
Second Order ◽  
Exchange Method ◽  
Screened Exchange ◽  
The Many

Hybrid functionals including random phase approximation correlation and second-order screened exchange

2010 ◽  
Vol 132 (9) ◽  
pp. 094103 ◽  
Author(s):  
Joachim Paier ◽  
Benjamin G. Janesko ◽  
Thomas M. Henderson ◽  
Gustavo E. Scuseria ◽  
Andreas Grüneis ◽  
...  
Keyword(s):  
Random Phase Approximation ◽  
Random Phase ◽  
Second Order ◽  
Phase Approximation ◽  
Screened Exchange ◽  
Hybrid Functionals

scholarly journals The GW Miracle in Many-Body Perturbation Theory for the Ionization Potential of Molecules

2021 ◽  
Vol 9 ◽  
Author(s):  
Fabien Bruneval ◽  
Nike Dattani ◽  
Michiel J. van Setten
Keyword(s):  
Perturbation Theory ◽  
Ionization Potential ◽  
Positive Impact ◽  
Second Order ◽  
Many Body ◽  
Hybrid Functional ◽  
Hartree Fock ◽  
Screened Exchange ◽  
Many Body Perturbation Theory ◽  
High Level

We use the GW100 benchmark set to systematically judge the quality of several perturbation theories against high-level quantum chemistry methods. First of all, we revisit the reference CCSD(T) ionization potentials for this popular benchmark set and establish a revised set of CCSD(T) results. Then, for all of these 100 molecules, we calculate the HOMO energy within second and third-order perturbation theory (PT2 and PT3), and, GW as post-Hartree-Fock methods. We found GW to be the most accurate of these three approximations for the ionization potential, by far. Going beyond GW by adding more diagrams is a tedious and dangerous activity: We tried to complement GW with second-order exchange (SOX), with second-order screened exchange (SOSEX), with interacting electron-hole pairs (WTDHF), and with a GW density-matrix (γGW). Only the γGW result has a positive impact. Finally using an improved hybrid functional for the non-interacting Green’s function, considering it as a cheap way to approximate self-consistency, the accuracy of the simplest GW approximation improves even more. We conclude that GW is a miracle: Its subtle balance makes GW both accurate and fast.

Erratum: “Hybrid functionals including random phase approximation correlation and second-order screened exchange” [J. Chem. Phys. 132, 094103 (2010)]

2010 ◽  
Vol 133 (17) ◽  
pp. 179902 ◽  
Author(s):  
Joachim Paier ◽  
Benjamin G. Janesko ◽  
Thomas M. Henderson ◽  
Gustavo E. Scuseria ◽  
Andreas Grüneis ◽  
...  
Keyword(s):  
Random Phase Approximation ◽  
Random Phase ◽  
Chem Phys ◽  
Second Order ◽  
Phase Approximation ◽  
Screened Exchange ◽  
Hybrid Functionals

Disappearance Voltage Determinations Using a Convergent Beam

1971 ◽  
Vol 29 ◽  
pp. 184-185
Author(s):  
W. L. Bell
Keyword(s):  
Second Order ◽  
Objective Method ◽  
Uniform Thickness ◽  
Rocking Curve ◽  
Crystal Perfection ◽  
Kikuchi Line ◽  
Central Maximum ◽  
Diffraction Patterns ◽  
Convergent Beam ◽  
Beam Technique

Disappearance voltages for second order reflections can be determined experimentally in a variety of ways. The more subjective methods, such as Kikuchi line disappearance and bend contour imaging, involve comparing a series of diffraction patterns or micrographs taken at intervals throughout the disappearance range and selecting that voltage which gives the strongest disappearance effect. The estimated accuracies of these methods are both to within 10 kV, or about 2-4%, of the true disappearance voltage, which is quite sufficient for using these voltages in further calculations. However, it is the necessity of determining this information by comparisons of exposed plates rather than while operating the microscope that detracts from the immediate usefulness of these methods if there is reason to perform experiments at an unknown disappearance voltage.The convergent beam technique for determining the disappearance voltage has been found to be a highly objective method when it is applicable, i.e. when reasonable crystal perfection exists and an area of uniform thickness can be found. The criterion for determining this voltage is that the central maximum disappear from the rocking curve for the second order spot.

Sign in / Sign up

Export Citation Format

Share Document