Bulletin of the American Physical Society
APS March Meeting 2018
Monday–Friday, March 5–9, 2018; Los Angeles, California
Session R02: Developments of DFT from Quantum to Statistical Mechanics (V)Focus

Hide Abstracts 
Sponsoring Units: DCP DCOMP Chair: Thomas Miller, Caltech Room: LACC 150B 
Thursday, March 8, 2018 8:00AM  8:36AM 
R02.00001: Finite temperature, classical DFT, and functionals from embedding Invited Speaker: Garnet Chan I will discuss a number of formal results in finite temperature and classical DFT. If time permits, I will also discuss quantum embedding theories from the viewpoint of functional construction. 
Thursday, March 8, 2018 8:36AM  8:48AM 
R02.00002: Valence electronic structure of cobalt phthalocyanine from an optimally tuned rangeseparated hybrid functional Georgia Prokopiou, Iulia Brumboiu, Leeor Kronik, Barbara Brena We analyze the valence electronic structure of cobalt phthalocyanine (CoPc) by means of optimally tuning a rangeseparated hybrid functional. The tuning is performed by modifying both the amount of shortrange exact exchange (α) included in the hybrid functional and the rangeseparation parameter (γ), with two strategies employed for finding the optimal γ for each α. The influence of these two parameters on the structural, electronic, and magnetic properties of CoPc is thoroughly investigated. The electronic structure is found to be very sensitive to the amount and range in which the exact exchange is included. The electronic structure obtained using the optimal parameters is compared to literature gasphase photoelectron data and GW calculations, with the unoccupied states additionally compared with inverse photoelectron spectroscopy measurements. The calculated spectrum with tuned γ, determined for the optimal value of α = 0.1, yields a very good agreement with both experimental results and with GW calculations that wellreproduce the experimental data. 
Thursday, March 8, 2018 8:48AM  9:00AM 
R02.00003: Asymptotic Analysis of Atomic Pauli Potentials Jeremy Redd, Antonio Cancio In orbital free (OF) DFT, the functional derivative of the Pauli contribution to the KohnSham kinetic energy, the Pauli potential, is key to solving for the density. It can be expressed as the Pauli kinetic energy per particle, plus a response potential which describes the response of this quantity to a change in density. We have constructed the exact response and Pauli potentials for closed shell atoms for which the former becomes an exact eigenvalue expression, extended to large Z atoms attainable only in theory. We have done this nonrelativistically because of the known asymptotic behavior of a semiclassical Fermielectron gas, which is the limit of the core electrons of an atom as nuclear charge approaches infinity. In this limit and as radius approaches zero, we can show that the Pauli potential approaches the magnitude of the lowest energy eigenvalue. We have also compared several gradient expansions to test their utility as orbital free approximations to the response potential. This research may help produce orbital free approximations to the Pauli potential with proper Z scaling, and by extension may generate OFDFT models that can solve for the density of both homogeneous and inhomogeneous systems. 
Thursday, March 8, 2018 9:00AM  9:12AM 
R02.00004: Nonlocal Kinetic Energy Functionals By Functional Integration Michele Pavanello Starting with the seminal works of Thomas and Fermi, the DensityFunctional Theory (DFT) community has been searching for accurate electron density functionals. The typical paradigm is to first approximate the energy functional, and then take its functional derivative yielding a potential that can be used in DFT simulations. In this work, we take a different route and construct the potential from the secondfunctional derivative by functional integration. Following this principle, we prescribe two nonlocal noninteracting Kinetic Energy functionals, $T_{s}[\rho]$, having density dependent and independent kernels, respectively. The functionals satisfy three exact conditions: (1) the existence of a “kinetic electron” arising from the existence of the exchange hole; (2) for homogeneous densities, the second functional derivative is the inverse Lindhard function; (3) potential and energy derive by functional integration of the second derivative involving a line integral. In pilot calculations the functionals are capable of reproducing Kohn–Sham DFT equilibrium volumes, bulk moduli, phase energy ordering and electron densities for CD, FCC, and BT Silicon as well as FCC Aluminum. Although more benchmark work is needed, the results are very encouraging. 
Thursday, March 8, 2018 9:12AM  9:24AM 
R02.00005: Nuclear quantum effect on hydrogen bond network fluctuation in liquid water inferred by Xray absorption spectra Zhaoru Sun, Lixin Zheng, Mohan Chen, Francesco Paesani, Xifan Wu Based on state of the art pathintegral molecular dynamics simulations carried out with the MBpol water model and calculations of electronic excitations within the selfconsistent GW theory, we investigate nuclear quantum effects (NQEs) on the oxygen Kedge Xray absorption spectra (XAS) of water at various temperatures. Under the influence of NQEs, protons are more delocalized, which significantly broadens the calculated XAS spectra. Furthermore, NQEs are responsible for nontrivial competing effects on the hydrogen bond network. On one hand, the liquid structure is slightly softened due to the presence of more broken hydrogen bonds. On the other hand, configurations with stronger hydrogen bonds are largely favored by proton delocalization. These competing NQEs yield important corrections on the calculated XAS spectra as demonstrated by red (blue) shifts of the mainedge (postedge). The calculated XAS spectra are in nearly quantitative agreement with the available experimental data. 
Thursday, March 8, 2018 9:24AM  9:36AM 
R02.00006: Constructing fragmentdensity functionals Kaili Jiang, Jonathan Nafziger, Adam Wasserman Approximations of the nonadditive noninteracting kinetic energy (NAKE) as an explicit functional of the density are the basis of fragmentbased methods that provide improved computational efficiency over standard KohnSham calculations. However, within most fragmentbased formalisms, there is no unique NAKE, making it difficult to develop general, robust approximations to it. In Partition Density Functional Theory, the ambiguity of the NAKE is removed and approximate functionals may be more meaningfully compared to exact quantities. We discuss promising avenues for constructing fragment densityfunctionals for the NAKE: (1) By reparametrizing decomposable conjoint functionals for weaklybonded systems; (2) By designing nondecomposable functionals for weak and covalent bonds that satisfy exact constraints of the partition energy without fitting. 
Thursday, March 8, 2018 9:36AM  10:12AM 
R02.00007: DFT beyond the groundstate: memorydependent functionals and coupling to ions Invited Speaker: Neepa Maitra The adiabatic approximations currently used in timedependent density functionals describe exchangecorrelation effects that depend only on the instantaneous density. However, recent work has shown that dependence on the history of the density and initial states is important to incorporate for accurate simulations of the dynamics, especially for systems driven far from the groundstate. In many applications when strong lasers are involved, the electron and nuclear dynamics happen on a similar timescale, especially when light nuclei are present, and the effects of correlation between the electron dynamics and quantum ion dynamics can be significant. 
Thursday, March 8, 2018 10:12AM  10:24AM 
R02.00008: Exact and Approximate Ensemble Density Functionals for a Simple model Francisca Sagredo, Kieron Burke Ensemble density functional theory (eDFT) has been of recent interest since it provides an alternative to the traditional timedependent density functional theory (TDDFT). Although TDDFT has many benefits, and is thus considered the standard method for solving for excited states, it still has many difficulties that are vital for understanding chemical processes. Such difficulties include: not being able to solve for multiple excitations, long range charge transfers, and conical intersections, thus making eDFT a useful alternative method to investigate. We have chosen the Hubbard dimer as the simple system to study where eDFT. This model is truncated to be a two site, dimer making all of the solutions analytic, and therefore a “toylike” model where we can control the correlation and the potential between the two sites. After derivation of simple functionals, the symmetry eigenstate hartree exchange approximation (SEHX) was tested for this model system. Using the SEHX approximation the first excited singlet state has been extracted for the dimer, as well as for the doubly occupied second excited state, which is a double excitation. Charge transfer excitations are also investigated. 

R02.00009: ABSTRACT WITHDRAWN

Thursday, March 8, 2018 10:36AM  10:48AM 
R02.00010: A unified treatment of derivative discontinuity, delocalization and static correlation effects in DFT: the LDA plus Density Matrix Minimization (LDA+DMM) method Fei Zhou, Vidvuds Ozolins

Thursday, March 8, 2018 10:48AM  11:00AM 
R02.00011: CAPDD: Improved Correct Asymptotic Potential GGA with Derivative Discontinuity Treatment Sam Trickey, Javier CarmonaEspindola, Jose Gazquez, Alberto Vela We summarize development and performance of a muchimproved nonempirical, constraintbased generalized gradient approximation (GGA) exchange functional which has exchange potentials with correct asymptotic behavior (1/r). It advances over our original “CAP” [J. Chem. Phys. 142, 054105 (2015)] via derivative discontinuity treatment and removal of a spurious midrange bump in the exchange potential. The mid and longrange behavior improvements follow from analysis of all sources of pure (1/r) asymptotic behavior and constraintbased combination of them. Derivative discontinuity is treated by internally consistent treatment of potential shift and approximate selfinteraction correction follows from exact calibration to the H atom. Calculated results for standard molecular tests (heats of formation, ionization potentials, electron affinities, bond lengths, barrier heights, etc.) as well as polarizabilities, hyperpolarizabilities, and treatment of excited states, show that the new CAPDD in many cases is superior to popular GGA functionals, always is competitive, and is competitive with such semiempirical hybrids as B3LYP. 
Follow Us 
Engage
Become an APS Member 
My APS
Renew Membership 
Information for 
About APSThe American Physical Society (APS) is a nonprofit membership organization working to advance the knowledge of physics. 
© 2019 American Physical Society
 All rights reserved  Terms of Use
 Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 207403844
(301) 2093200
Editorial Office
1 Research Road, Ridge, NY 119612701
(631) 5914000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 200452001
(202) 6628700