Low-order scaling and accurate GW calculations with ADF
The GW method has become an increasingly popular method to calculate charged excitations in molecules. However, achieving consensus between different GW codes is challenging since GW calculations are very sensitive with respect to many technical parameters, including the choice of a single-particle basis as well as a discretization of frequency and/or time-variables.
In a recent paper(1), excellent agreement of the low-order scaling G0W0 implementation in ADF(2) with other established codes, including TURBOMOLE, FHI-AIMS, and VASP, has been achieved for the challenging GW100 database. This has been accomplished by newly updated imaginary time and frequency grids as well as newly designed, correlation-consistent Slater-type basis sets for the whole periodic table. With these new basis sets, the complete basis set limit can be reached by extrapolation from a triple- and a quadruple-zeta calculation. The basis sets are also available with extra diffuse functions which are important to give accurate negative electron affinities.
The new basis sets are also very useful for all many-body perturbation theory calculations in ADF, including MP2(3), RPA, and double hybrids(4) (see also other highlight).
ADF 2021 also has an implementation of eigenvalue-only self-consistent GW (evGW).
(1) Arno Förster, Lucas Visscher, GW100: A Slater-Type Orbital Perspective, J. Chem. Theory Comput. 2021 17, 5080
(2) Arno Förster, Lucas Visscher, Low-order scaling G0W0 by Pair Atomic Density Fitting, J. Chem. Theory Comput. 2020, 16, 12, 7381–7399
(3) Arno Förster, Mirko Franchini, Erik van Lenthe, Lucas Visscher, A Quadratic Pair Atomic Resolution of the Identity Based SOS-AO-MP2 Algorithm Using Slater Type Orbitals, J. Chem. Theory Comput. 2020, 16, 2, 875–891
(4) Arno Förster, Lucas Visscher, Double hybrid DFT calculations with Slater type orbitals, J. Comput. Chem. 2020, 41:1660–1684