BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:g-xTB: DFT accuracy at tight-binding speed - Professor Stefan Grim
 me\, University of Bonn
DTSTART:20250305T143000Z
DTEND:20250305T153000Z
UID:TALK222364@talks.cam.ac.uk
CONTACT:Lisa Masters
DESCRIPTION:Recently\, we optimized small (vDZP)\, deeply contracted AO ba
 sis sets in molecular DFT calculations using standard ECPs for all element
 s up to radon[1]. This strategy is further- more applied to a minimal set 
 of AOs which — as a totally new ingredient — is made adaptive\, i.e.\,
  radially different for symmetry distinct atoms in a molecule. The ”brea
 thing” of the AOs in the molecular environment is parameterized efficien
 tly by on-the-fly computed effective atomic charges (obtained by a new EEQ
  charge model) and coordination numbers. This so-called q-vSZP set[2] prov
 ides in typical DFT applications results of about or better than DZ qualit
 y. It forms the basis of our third-generation tight-binding model g-xTB (g
 =general). This includes non-local Fock-exchange as well as other new\, ma
 ny-center Hamiltonian terms (e.g.\, atomic correction potentials\, ACP). I
 t aims at general purpose applicability in chemistry and more closely appr
 oaches DFT accuracy (actually ωB97M-V/aTZ[3]) than previous semi-empirica
 l methods at only slightly increased computational cost (factor of 1.5 com
 pared to GFN2-xTB). It will be consistently available for all elements Z=1
 -103 with f-electrons included for lanathanides/actinides. The talk descri
 bes key improvements of the underlying TB theory as well as extensive benc
 hmarking on a wide range of standard thermochemistry sets.\n[1] M. Müller
 \, A. Hansen\, S. Grimme\, J. Chem. Phys. 158 (2023)\, 014103\n[2] M. Mül
 ler\, A. Hansen\, S. Grimme\, J. Chem. Phys. 159 (2023)\, 164108. Revision
 : JPC A\, doi:10.1021/acs.jpca.4c06989\n[3] N. Mardirossian and M. Head-Go
 rdon\, J. Chem. Phys. 144 (2016)\, 214110
LOCATION:Unilever Lecture Theatre\, Yusuf Hamied Department of Chemistry
END:VEVENT
END:VCALENDAR