|Événements du mois|
Dans le cadre du projet "Nano for sensors", l'Institut Jean Lamour et Lorraine Université d'Excellence invitent le Professeur Richard Dronskowski (Chair of Solid-State and Quantum Chemistry RWTH Aachen University, Aix-la-Chapelle, Allemagne) pour un séminaire intitulé :
"New Aspects of Chemical Bonding in Solids using Orbitals and Plane Waves"
Date et lieu :
Vendredi 16 novembre 2018 à 14h00
Ecole des Mines
Campus Artem, Nancy
Population analysis as imagined by Mulliken (1955) has held a prominent place in quantum chemistry fordecades already.
Likewise, periodic bonding indicators such as COOP (introduced in 1983) and its DFT equivalent COHP (from 1993) have been helpful, the latter carried out using local-basis codes such as TB-LMTO-ASA.
COHP analysis has allowed to chemically understand three-dimensional Peierls distortions, spin polarization in itinerant magnets, stoichiometries of phase-change materials, and a lot more.
While plane-wave packages such as VASP, ABINIT, Quantum ESPRESSO etc. offer computational advantages compared to LMTO, they lack locality, so the aforementioned chemical concepts were unavailable.
Nonetheless, the local COHP information can be analytically reconstructed by transferring PAW pseudopotential data to local bases built from contracted STOs, as implemented in the LOBSTER code (www.cohp.de), and it also allows for other tools like the density-of-energy (DOE) and well-established quantum-chemical descriptors such as Mulliken or Löwdin charges.
All that will be illustrated, using essentially non-mathematical reasoning, from recent examples such as carbon (nanotube), 4f hexaborides, Ge4Se3Te, In2Se3, Pb2Si5N8, and Na2He.
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