Z39: Theory and Computation; Surfaces and Interfaces
Fri. March 8, 11:30 a.m. – 2:30 p.m. CST
103E
Sponsoring Units: DCPChair: Yuhua Duan, Natl Energy Technology Lab
Fri. March 8, 12:30 p.m. – 12:42 p.m. CST
103E
The poles of the single-particle Green’s function correspond to the electron addition and removal energies probed in direct and inverse photoemission experiments, and thus provide a direct link between theory and experiment. One way to extract such energies is to use the GW approximation to the self-energy, a popular method in electronic structure theory. Like other nonlinear methods, the GW quasiparticle equations should be solved self-consistently, however, comparatively few fully self-consistent (scGW) solutions have been performed throughout the years due to their high computational cost. Non-self-consistent alternatives, like the one-shot G0W0 demand less computational resources but depend on the mean-field orbitals and energies that are used as input. Furthermore, G0W0 energies are not good starting points to obtain accurate neutral excitations using the Bethe-Salpeter Equation (BSE) formalism in finite systems. The simplest way to incorporate more physics is to iterate the eigenvalues (evGW) until they remain self-consistent, an effort that comes at a higher computational cost. In this talk, we will show that including an approximation to the derivative discontinuity (DD) of the nearly correct asymptotic potential (NCAP) exchange-correlation functional yields G0W0@NCAP-DD quasiparticle energies comparable to the more expensive evGW@GGA energies.
Presented By
Daniel Mejia-Rodriguez (Pacific Northwest National Laboratory (PNNL))
Authors
Daniel Mejia-Rodriguez (Pacific Northwest National Laboratory (PNNL))
Niranjan Govind (Pacific Northwest National Laboratory)
Edoardo Aprà (Pacific Northwest National Laboratory)
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evGW ionization potentials at G0W0 cost
Fri. March 8, 12:30 p.m. – 12:42 p.m. CST
103E
The poles of the single-particle Green’s function correspond to the electron addition and removal energies probed in direct and inverse photoemission experiments, and thus provide a direct link between theory and experiment. One way to extract such energies is to use the GW approximation to the self-energy, a popular method in electronic structure theory. Like other nonlinear methods, the GW quasiparticle equations should be solved self-consistently, however, comparatively few fully self-consistent (scGW) solutions have been performed throughout the years due to their high computational cost. Non-self-consistent alternatives, like the one-shot G0W0 demand less computational resources but depend on the mean-field orbitals and energies that are used as input. Furthermore, G0W0 energies are not good starting points to obtain accurate neutral excitations using the Bethe-Salpeter Equation (BSE) formalism in finite systems. The simplest way to incorporate more physics is to iterate the eigenvalues (evGW) until they remain self-consistent, an effort that comes at a higher computational cost. In this talk, we will show that including an approximation to the derivative discontinuity (DD) of the nearly correct asymptotic potential (NCAP) exchange-correlation functional yields G0W0@NCAP-DD quasiparticle energies comparable to the more expensive evGW@GGA energies.
Presented By
Daniel Mejia-Rodriguez (Pacific Northwest National Laboratory (PNNL))
Authors
Daniel Mejia-Rodriguez (Pacific Northwest National Laboratory (PNNL))
Niranjan Govind (Pacific Northwest National Laboratory)
Edoardo Aprà (Pacific Northwest National Laboratory)