#### All News

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#### Oct. 18, 2018

Alert! A bug in the pressure calculation of our PROFESS@QE package has been fixed. Please see the Computation page to download the corrected tarball.

#### Sept. 24, 2018

Please join us in welcoming Dr. Dongdong Kang for a one-year visit in our group. He is from the Department of Physics, National University of Defense Technology, Changsha China.

#### April 25, 2018

We've initiated a new resource. Under Reference Data, we've put up a first implementation of a pop-up periodic table that enables the user to get atomic kinetic energies for many different orbital-free KE functionals. We will be improving and extending this and other technical data resources. Suggestions are welcome. Thanks to Kai Luo and Daniel Mejia-Rodiguez for doing the calculations and preparing the presentation.

#### April 16, 2018; update May 23

For those who read Spanish, the article about the ceremony for Sam Trickey's admission as a Corresponding Member of the Academia Mexicana de Ciencias in the "Boletin Informativo" is here. A related article is at the Academy's news site. And an interview is here .

#### March 12, 2018

It is a pleasure to welcome Angel Martín Albavera Mata for a three-month visit. Angel is a Ph.D. student with Prof. Alberto Vela at CINVESTAV-Zacatenco in Mexico City. His work here will be on testing and validation of the performance on solids of the various Mexican collaboration exchange-correlation functionals. This is an important topic for the progress of orbital-free DFT, as those functionals are all generalized-gradient approximations.

#### Feb. 14, 2018

After repeated, almost inexplicable delays, our Valentine's present is the appearance (at last!) of our generalized gradient approximation for the exchange-correlation free energy, KDT16. See Phys. Rev. Lett. 120, 076401 (2018) on Publications.

#### August 15, 2017

Jeff Wrighton has been a collaborator with Jim Dufty for several years. It is a pleasure to announce that Jeff has formally joined the group.

#### July 24, 2017

With appreciation for his many contributions, mixed with understandable (we trust) regret at his departure, we are proud to report that Valentin Karasiev has taken a Staff Scientist position in the High-energy Density Physics Group of the Laboratory for Laser Energetics, University of Rochester.

#### June 23, 2017

Today we are happy to announce the first public release of our Kubo-Greenwood electrical conductivity post-processor package for use with QuantumEspresso. The KGEC code and Guide are available from our Computation page and the paper that describes both the underlying analysis and the implementation is downloadable from Publications.

#### June 11, 2017

It is gratifying to report that the book Frontiers and Challenges in Warm Dense Matter [Springer] continues to draw interest as measured by eBook chapter downloads. The numbers are 1,572 [2016], 1,597 [2015], and 1,822 [2014]. The book grew out of the 2012 IPAM long program on high energy density physics in which several members of our group participated. The book editors are Frank Graziani, Michael Desjarlais, Ronald Redmer, and Sam Trickey.

#### April 3, 2017

Congratulations to Lázaro Calderín, who has gone to the College of Engineering, Univ. of Arizona, as Assistant Research Professor. Among other contributions, Lázaro led the Kubo-Greenwood code development project.

#### March 23, 2017

The LibXC initialization test for our KSDT functional has been updated to include C code as well as the previous Fortran code. See the "LSDA Exchange-Correlation Free Energy Subroutines" item on the Computation page and the paper on the underlying, the algorithms, and implementation is on our

#### March 19, 2017

Newly posted on the Presentations page are the PDFs for our four presentations at the APS March meeting last week.

#### Dec. 19, 2016

On the Publications page, take a look at the manuscript announcing our new finite-T Generalized Gradient Approximation exchange-correlation functional, KDT16. It reduces to PBE at T=0 K but gives noticeably different pressures in, for example, Al and deuterium at temperatures into the WDM regime.

#### Dec. 12, 2016

We are happy to announce that Sam Trickey has been named a Corresponding Member of the Academia Mexicana de Ciencias in recognition of his long, extensive involvement in materials physics and chemical physics research in México.

#### TWO POSTDOC POSTS

Both positions now have been filled. For context, the advertisement letter still is posted.

#### June 15, 2016

The LibXC implementation of our KSDT local spin density approximation exchange-correlation free energy functional will not initialize properly if called in the standard way. A HOWTO file which explains the extra initialization and a set of simple test routines now is available from Computation.

#### May 10, 2016; Update June 13

Deb got married! Congratulations to him and Aindrila. And he is leaving. We wish him well. The wedding celebration reception here in Gainesville was May 1st. A photo from that event is on the People page.

#### March 2, 2016

Version 2 of PROFESS@QuantumEspresso is released! The main change is utilization of PROFESS version 3.0 and QuantumEspresso version 5.2.1. The README and new tarball are downloadable from Computation. Licensure continues to be GNU GPL. Give the package a try. Let us know what you think.

#### Dec. 18 and 23, 2015

Our KSDT LSDA exchange-correlation free energy functional is in LibXC v3.0.0, which is to be released. (Presently it is listed as KSDT2; we have asked that this be corrected.) We will provide a test code and data downloadable from here when the LibXC version is released. Meanwhile, the LibXC development version that includes KSDT is downloadable from the LibXC svn repository. Go to the LibXC download page and scroll down for the instructions.

#### June 17, 2015

Subroutines to evaluate the LSDA exchange-correlation free energy functional now are downloadable from the Computation page. Details of this KSDT functional, which was obtained by fitting to high-precision path-integral Monte Carlo data, are in Phys. Rev. Lett. 112, 076403 (2014); see Publications The subroutines are substantially the same as those in our PROFESS@Quantum-Espresso (version 1) package. As customary, licensure is GNU GPL.

#### June 10, 2015

Travis Sjostrom of Los Alamos National Lab (and an alumnus of our group) is visiting. He will present a talk on his recent work on Friday, 12 June, 2:00 pm.

#### Jan. 22, 2015

We are pleased to welcome Dr. Lázaro Calderín to the group. He began last week. Until logistics of his move from Penn State to Gainesville are completed, he will be working remotely. Initially he will be working on temperature effects in calculated spectra.

#### Nov. 7 and 19, 2014

High-precision, smooth fits to various commonly encountered combinations Fermi-Dirac integrals are treated in our new paper. The fits have smooth derivatives, an important property lacking in several of their predecessors. The reprint is available on the publications page. Nov. 19 update: GPL-licensed software for these fits now is available for download from the Computation page.

#### July 1, 2014

"Frontiers and Challenges in Warm Dense Matter" is out. This book collects papers written after the IPAM Warm Dense Matter workshop in Spring 2012 by participants. Springer is the publisher. Editors are Frank Graziani, Michael Desjarlais, Ronald Redmer, and Sam Trickey. Here's the cover image . Reprint of our chapter "Innovations in Finite-Temperature Density Functionals" is available from Publications.

#### June 4, 2014

Our PROFESS@Quantum-Espresso software for driving ab initio MD in Quantum-Espresso with our OFDFT functionals in PROFESS (and T-dependent XC in Q-E) now is available for download from the Computation page. The paper describing the implementation is available from Publications.

#### April 16, 2014

With pleasure we welcome Prof. Michael Bonitz of the Chair in Statistical Physics (Lehrstuhl Statistische Physik), Christian Albrechts Universitaet zu Kiel. He will be spending parts of his sabbatical in Univ. of Florida Physics over the next few months. Today his informal presentation is on recent path integral Monte Carlo work on many-fermion systems, notably the uniform electron gas.

#### March 11, 2014

This week and next, Prof. Jim Lutsko of the Center for Nonlinear Phenomena and Complex Systems of the Universite' Libre de Bruxelles (Belgium) is visiting. Discussion presentations on 11, 13, and 14 March will focus on the relationships of classical and quantum density functional theory.

#### Feb. 10, 2014

Welcome to Eyal Segev (Hebrew University of Jerusalem) this week. He is a member of Prof. Doron Gazit's group in the Racah Institute of Physics. His talk tomorrow is entitled "The Leading Correction to the Thomas-Fermi Model at Finite Temperature in a Functional Form".

#### Jan. 15, 2014

Update: our finite-temperature LSDA paper has been accepted by Phys. Rev. Lett. The accepted version, which has small editorial revisions, is accessible from Publications. Postscript (10 Feb.): the editors changed the title several times. The eventual title is on the version now posted.

#### Dec. 19, 2013

We have posted a corrected version of our finite-temperature LSDA paper and supplemental information. Go to Publications. Some of the parameters in Table I of the previous version were incorrect, so if you downloaded that version, please discard it. None of the conclusions of the paper are changed and changes in the figures are essentially indiscernible.

#### Dec. 16, 2013

This week Debajit Chakraborty will present a talk to M4 = "Methods for Modeling Molecules and Materials", at Mc Master University. Last week, Sam Trickey took part in the Reunion Meeting of the 2012 Long Program on High Energy Density Plasmas of the Inst. of Pure and Applied Mathematics, UCLA. Both talks presented our group's recent progress on two fronts: a fully non-empirical, orbital-free non-interacting free-energy functional in the generalized gradient approximation and a finite-T exchange-correlation functional purely from restricted path integral Monte Carlo data. A reprint of the former paper and a preprint of the latter are posted at Publications under The Research.

#### Sept. 1, 2013

It is a pleasure to announce that our Dept. of Energy grant has been renewed for three years, effective today. The grant is under the Theoretical Condensed Matter Physics Program of the Division of Materials Sciences and Engineering in the Office of Basic Energy Sciences. The Program Officer is Dr. James Davenport.

#### July 26, 2013

Two additional pseudopotentials are available for download. The first is the Al local Heine-Abarenkov PP in reciprocal space for use with Profess and CASTEP. The second is our local regularized PP for H, published previously in reciprocal space form in the the format for Profess, now also in UPF format for Quantum Espresso. Go to Computation under The Research.

#### July 10, 2013

Valentin Karasiev and Sam Trickey presented Constraint-based development of finite-temperature. orbital-free density functionals'' and Orbital-free molecular dynamics for warm dense hydrogen and deuterium'', at the Warm Dense Matter 2013 meeting (Saint Malo France) 23-26 June. Sam also gave the opening talk at the CECAM-Berlin 2013 meeting Density Functional Theory: Learning From the Past, Looking to the Future'', 2-5 July 2013. The title was`Fast ab initio MD with Non-empirical Orbital-free Density Functionals''.

#### April 11, 2013

The visitor program for this academic year concluded yesterday with the second of two presentations by Paul Grabowski (Los Alamos National Laboratory). Paul presented talks on numerical studies of the limitations of wave-packet molecular dynamics for high energy density systems and on MD simulations of stopping to test kinetic models in such systems.

#### Mar. 7, 2013

Our transferable pseudopotentials and projector augmented wave data sets now are available for download. Go to Computation under The Research.

#### Feb. 15, 2013

Thanks to Michael Desjarlais (Sandia National Laboratory, Albuquerque NM) for two full days (just completed) of stimulating discussions on density functional methods in the context of ab initio molecular dynamics. Some of the major topics in the wide-ranging conversations were transport calculations and their underlying formulation, reliable calculation of Hugoniots, characterization of phase boundaries in light and heavy metals (including opportunities to use our newly developed finite-T orbital-free functionals), and systematic code and methodology comparisons.

#### Jan. 28, 2013

We welcome Richard W. Lee (Institute for Material Dynamics at Extreme Conditions, Physics Dept., U. Calif. Berkeley) today and tomorrow for extensive discussions on experimental probes of WDM. The non-uniformities which have been found in multiple experiments have considerable significance for some of the theoretical assumptions on which the great majority of computational treatments of WDM are based.

#### Jan. 8, 2013

Travis Sjostrom has left to join group T-5 at Los Alamos National Laboratory. In late Fall 2012, Tamás Gál left to take up a faculty position in Theoretical Physics at the Univ. of Pecs, Hungary. Congratulations to both Támas and Travis!

#### Jan. 4, 2013

Frank Harris is co-author of the newest edition of the famous Arfken text. The bibliographic reference is: "Mathematical Methods for Physicists, 7th edition", George B. Arfken, Hans J. Weber, and Frank E. Harris (Academic Press, 2013). In other similar professional activities, Jim Dufty is a co-editor of the Proceedings of the 14th International Conference on Non-ideal Plasmas, and Sam Trickey was just reappointed to another three-year term as Specialist Editor (Condensed Matter Physics) for Computer Physics Communications .

#### Sept. 5-7 & 10-14, 2012

Four of us (Jim Dufty, Valentin Karasiev, Travis Sjostrom, and Sam Trickey) presented talks at the CECAM Workshop (Paris) entitled "Orbital-free Approach to High Energy Density Physics". Here's a PDF of the agenda. See the link at the right as well.

Condensed matter and materials physics is growing in scope and reach. After the CECAM Workshop, the delegation went to Rostock Germany for PNP-14; see the link at right. From the program, it is increasingly clear that WDM problems are much better addressed in detail by taking the methods of condensed matter and materials physics upwards in temperature and pressure than by attempting to stretch standard plasma methods downward. Our presentations were emblematic of that trend.

#### May 21-25, 2012

We presented papers and helped organize the "Workshop on Computational Challenges in Warm Dense Matter" at the Institute of Pure and Applied Mathematics (IPAM), U. California Los Angeles. This was Workshop IV of the IPAM "Long Program on Computational Methods in High Energy Density Plasmas". PDFs of presentations by Jim Dufty, Travis Sjostrom, and Sam Trickey may be obtained from the Workshop webpage at IPAM.

#### Feb. 27, 2012

Our PI, Sam Trickey, was one of 149 Outstanding Referees named this year by the American Physical Society. The announcement was at the "March meeting". He joins one of our co-PIs, Jim Dufty, who received the same honor in 2009. This is a lifetime award. According to the APS, about 150 referees are honored each year out of about 60,000 currently active referees. The full list is available from the APS.

#### Nov. 14-18, 2011

A mini-conference was held on "Dense Quantum Plasma Simulation" at the APS Division of Plasma Physics meeting, Salt Lake City, November 14-18. The mini-conference, organized by Michael Bonitz, Jim Dufty, and Frank Graziani, was comprised of two oral sessions Nov. 17 and 18 and a poster session. Please see this outline for more information or Michael Bonitz' website for abstracts of invited talks.

Talks given from this group (in pdf):
Restricted Path-Integral Molecular Dynamics for Simulating the Correlated Electron Plasma in Warm Dense Matter
Vivek Kapila (co-authors Pierre Deymier and Keith Runge)
Temperature-Dependent Behavior of Confined Many-electron Systems in the Hartree-Fock Approximation
Travis Sjostrom (co-authors Frank Harris and Sam Trickey)

Posters:
Finite-Temperature Orbital-free Density Functional Calculations for Warm Dense Lithium
Valentin Karasiev (co-authors Travis Sjostrom and Sam Trickey)
Classical Representation of a Quantum System at Equilibrium
Sandipan Dutta (co-author James Dufty)

#### Sept. 9, 2011

Scaling, bounds, and inequalities for the noninteracting density functionals at finite temperature was published as an Editors' Suggestion in Physical Review B.
James W. Dufty and S.B. Trickey, Phys. Rev. B 84, 125118 (2011) PDF

#### Sept. 7-9, 2011

Sam Trickey gave an invited talk, found here, entitled Temperature-Dependent Behavior of Confined Many-electron Systems in the Hartree-Fock Approximation at the "First International Workshop on Studies of Confined Quantum Systems" held at the Universidad Metropolitana Autonoma - Iztapalapa, Mexico City.

#### July 24-29, 2011

The Strongly Coupled Coulomb Systems 2011 conference was held in Budapest, Hungary. Jim Dufty contributed a talk entitled Classical Representation of a Quantum System at Equilibrium, which can be found here.

#### May 30-31, 2011

Jim Dufty and Sam Trickey gave invited talks at "The Orbital-free Alternative" workshop, held at the Institut Henri Poincaré, Paris, May 30-31, 2011. This was a discussion meeting sponsored by the French node of CECAM (Centre Européen de Calcul Atomique et Moléculaire). Jim's talk was entitled "Properties of the Finite Temperature Non-Interacting Density Functionals". Sam's was "Coherent Approach to Orbital-free DFT". There was ample time for really fruitful, detailed discussion.

The purpose was to assess the opportunity and need for a full CECAM workshop on orbital-free DFT. The conclusion was that the main need is to focus primarily on finite- temperature OF-DFT, with the zero-temperature problem as a crucial limiting case. Several hours were devoted to crafting a list of key elements for a proposal to CECAM to fund such a meeting. Thanks go to our colleagues Flavien Lambert and Jean Clérouin for organizing this very fruitful gathering.

A program for the meeting, including abstracts for the talks can be found here.

#### March 21-25, 2011

At the APS March meeting, Dallas, five talks were given by the group. Abstracts can be found below

Reference Calculation of Temperature-dependent Behavior of Confined Many-electron Systems
All-Electron and Pseudopotential Orbital-Free Density Functional Calculations
Finite-temperature Exchange and Correlation Functionals in Self-Consistent Calculations
Contributions to the Non-interacting Free Energy Density Functional
Finite Temperature Scaling of the Non-interacting Free Energy Density Functional

#### February 27, 2011

51st Annual Sanibel meeting was held Feb. 25 - Mar. 1. Two sessions devoted to warm dense matter were organized including speakers Michael Desjarlais, Chandre Dharma-wardana, Flavien Lambert, Burkhard Militzer, Andrew Ng, and Frank Graziani. Following talks a poolside roundtable meeting was held with the speakers and the group. Abstracts of the talks can be found here under Plenary VIII and IX.

#### December 15-20, 2010

The PacifiChem 2010 meeting was attended by Valentin Karasiev, where he gave an invited talk on new work in an OFDFT session entitled Recent advances in development of single-point orbital-free kinetic energy functionals, found here.

#### November 15-18, 2009

The report of the DOE workshop on Basic Research Needs for High Energy Density Laboratory Physics was published Oct. 2010. It can be found here. Sam Trickey was a member of the warm dense matter sub-group. Its report is chapter 6.

#### September 2009

A new Dept. of Energy project development of orbital-free free-energy density functionals started at UF. Target physical systems are in the Warm Dense Matter regime: systems with electron temperatures of order 10 electron volts at solid densities. Co-PIs are Sam Trickey, Jim Dufty, Frank Harris, and Keith Runge. This is an outgrowth of zero-temprature work with Valentin Karasiev (IVIC, Venezuela) and Frank Harris on developing orbital-free approximations to the Kohn-Sham kinetic energy to use in calculating Born-Oppenheimer forces in fast molecular dynamics simulations.