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SUMMARY:MARVEL Distinguished Lecture – John Perdew
DTSTART:20211115T150000
DTEND:20211115T161500
DTSTAMP:20260407T210929Z
UID:966a1d56a599793236a1b67c2043c891f46aea2c753152005a03d519
CATEGORIES:Conferences - Seminars
DESCRIPTION:John Perdew (Temple University)\nhttps://epfl.zoom.us/j/635508
 06441\nPasscode: 2517\n\nJohn Perdew\nProfessor of Physics and Chemistry\,
  Temple University\, Philadelphia (USA)\n\nMore-predictive density functio
 nals\, symmetry breaking\, and strong correlation\nApproximate density fun
 ctionals constructed to satisfy known mathematical properties of the exact
  density functional for the exchange-correlation energy of a many-electron
  system can be predictive over a wide range of materials and molecules. Th
 e strongly constrained and appropriately normed (SCAN) meta-generalized gr
 adient approximation [1] satisfies 17 exact constraints\, and nicely descr
 ibes some systems that were formerly thought to be beyond the reach of den
 sity functional theory\, such as the cuprates [2]. In some cases (e.g.\, b
 arrier heights to chemical reactions and hydrogen bonds in water [3])\, SC
 AN is dramatically more accurate when evaluated on the Hartree-Fock densit
 y than it is on its own self-consistent and more delocalizing density. Gro
 und states that break the symmetry of a Coulomb-interacting Hamiltonian ca
 n be understood as dynamic density or spin-density fluctuations that drop 
 to low or zero frequency [4\,5] and so persist over long times. In many ca
 ses\, symmetry breaking transforms the strong correlation in a symmetry-un
 broken wavefunction into moderate correlation like that found in the unifo
 rm electron gas of high or valence-electron density (an “appropriate nor
 m” for constraint-based approximations).\nSupported by NSF DMR-1939528.\
 n[1] J. Sun\, A. Ruzsinszky\, and J.P. Perdew\, Phys. Rev. Lett. 115\, 03
 6402 (2015)\n[2] J.W. Furness\, Y. Zhang\, C. Lane\, I.G. Buda\, B. Barbie
 llini\, R.S. Markiewicz\, A. Bansil\, and J. Sun\, Commun. Phys. 1\, 11 (
 2018)\n[3] S. Dasgupta\, E. Lambros\, J.P. Perdew\, and F. Paesani\, Natur
 e Commun. accepted\n[4] P.W. Anderson\, Science 177\, 393 (1972)\n[5] J.P
 . Perdew\, A. Ruzsinszky\, J. Sun\, N.K. Nepal\, and A.D. Kaplan\, Proc. N
 at. Acad. Sci. USA 118\, e2017850118 (2021)\n\nAbout the speaker\nJohn Pe
 rdew’s research in the Hohenberg-Kohn-Sham density-functional theory of
  electronic structure has helped to establish this theory as the most wid
 ely-used method to predict the properties of atoms\, molecules\, and soli
 ds from the principles of quantum mechanics. A density functional is a fo
 rmula that expresses the energy of a many-electron system in terms of its
  electron density\, facilitating the easy computer calculation of both. Pe
 rdew and his collaborators have discovered some unexpected properties of 
 the exact density functional\, including its derivative discontinuity and
  scaling properties\, and more recently a strongly-tightened lower bound o
 n the exchange energy. They have also constructed a ladder of nonempirica
 l approximations to the exact functional\, on which higher rungs are more 
 complex and more accurate.  In essence\, they have been making educated 
 guesses at the rule for “nature’s glue” that binds electrons into a
 toms and atoms into molecules and solids. They seek functionals that are 
 rooted in physical principles and work reliably for atoms\, molecules\, so
 lids\, surfaces\, and molecules on surfaces. Their functionals are built i
 nto standard computer codes\, and are widely used by both physicists and 
 chemists. Current research includes the development of better meta-genera
 lized gradient approximations from a dimensionless ingredient that can rec
 ognize and assign appropriate descriptions to covalent\, metallic\, and w
 eak bonds.\nJohn Perdew earned his PhD from Cornell University. After post
 doctoral fellowships at the Universities of Toronto and Rutgers\, he was a
 ppointed faculty as the department of physics of Tulane University. Since 
 2013 he has been a professor at the department of physics of Temple Univer
 sity in Philadelphia.\n\n 
LOCATION:https://epfl.zoom.us/j/63550806441?pwd=SEQwbVhPZVNMSmcwaWtBRDJvaU
 pEdz09
STATUS:CONFIRMED
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