NAPS
Nanoscopic Physics
Prof. Richard Dronskowski
Chair of Solid-State and Quantum Chemistry, Institute of Inorganic
Chemistry, RWTH Aachen University, Germany
will give a seminar entitled
Chemical Bonding (in Solids) from
Local Orbitals and Plane Waves
on Friday 26th August 2016, 10:45 a.m.,
NAPS seminar room E032
(Marc de Hemptinne - SC01, Chemin du Cyclotron, 2 – LLN)
NAPS
Nanoscopic Physics
Population analysis [1] holds a prominent place in quantum chemistry, namely for bonding
studies of simple but also complex molecules. Likewise, for decades already three-dimensional
periodic bonding indicators such as Crystal Orbital Overlap Population (COOP) [2] and Crystal
Orbital Hamilton Population (COHP) [3,4] have been helpful, the latter using DFT combined
with local-basis codes such as tight-binding LMTO-ASA. COHP analysis has allowed to
chemically understand three-dimensional Peierls distortions, spin polarization in itinerant
(ferro)magnets, stoichiometries of phase-change materials, and a lot more. While plane-wave
PAW packages such as VASP, ABINIT, Quantum ESPRESSO etc. offer huge computational
advantages, they lack locality, so the aforementioned chemical concepts were so far
unavailable. Nonetheless, local information can be reconstructed to yield projected COHPs
[5], and one may also generate an analytical framework to transfer PAW functions to a
localized basis built from Slater-type orbitals [6]. Technically, multiple Slater functions are
contracted to match real atomic functions and serve as an adequate choice to yield the desired
linear-combination coefficients. Thus, the projected analogues to the density-of-states (DOS),
COOP and COHP are readily available, and they have been implemented in the computer
program LOBSTER (www.cohp.de) to derive all of the aforementioned quantities from PAW
calculations [7]. By doing so, surfaces, open structures, amorphous matter, molecular crystals,
molecules etc. may also be chemically understood although crunched through plane waves.
[1]
[2]
[3]
[4]
[5]
[6]
[7]
R. S. Mulliken, J. Chem. Phys. 1955, 23, 1833.
T. Hughbanks, R. Hoffmann, J. Am. Chem. Soc. 1983, 105, 3528.
R. Dronskowski, P. E. Blöchl, J. Phys. Chem. 1993, 97, 8617.
R. Dronskowski, Computational Chemistry of Solid State Materials, Wiley-VCH,
Weinheim, New York 2005.
V. L. Deringer, A. L. Tchougréeff, R. Dronskowski, J. Phys. Chem. A 2011, 115, 5461.
S. Maintz, V. L. Deringer, A. L. Tchougréeff, R. Dronskowski, J. Comput. Chem. 2013, 34,
2557.
S. Maintz, V. L. Deringer, A. L. Tchougréeff, R. Dronskowski, J. Comput. Chem. 2016, 37,
1030.
For more information please contact : Vinciane Gandibleux