THE ANNUAL DEIXIS2010 DEPARTMENT OF ENERGY COMPUTATIONAL SCIENCE GRADUATE FELLOWSHIP SCIENCE GRADUATE OF ENERGY COMPUTATIONAL DEPARTMENT DETONATION DETERMINATION Alejandro Rodriguez’s Practicum Provides an ”Explosive” Surprise PAGE 5 THE ANNUAL DEIXIS TABLE OF CONTENTS 13 20 DEIXIS, The DOE CSGF Annual is published by the Krell Institute. The Krell Institute administers the Department of Energy Computational Science Graduate Fellowship program for the DOE under contract DE-FG02-97ER25308. For additional information about the Department of Energy Computational Science Graduate 5 Fellowship program, the Krell Institute or topics 17 22 covered in this publication, please contact: Editor, DEIXIS The Krell Institute 1609 Golden Aspen Drive, Suite 101 Ames, IA 50010 OUR NEW LOOK (515) 956-3696 www.krellinst.org/csgf 4 20 26 Since 2002, DEIXIS, the journal of the Department of Energy Practicum Profiles Alumni Profiles Winning Essays Copyright 2010 by the Krell Institute. Computational Science Graduate Fellowship (DOE CSGF), has The Pause That Refreshes Graduates Notch Achievements Encouraging Communication All rights reserved. connected fellows, attracted applicants, and informed academics and policy-makers about computational science and one of the 5 Alejandro Rodriguez 20 Michael Wu 26 Anubhav Jain, Winner nation’s top education programs. Now DEIXIS has a new look and Detonation Determination Researcher Tunes Why Don't Batteries DEIXIS (ΔΕΙΞΙΣ) transliterated from classical Greek into the Roman alphabet, (pronounced da¯ksis) means a display, a greater focus on fellows and alumni. Into Networks Improve Like Transistors? mode or process of proof; the process of showing, proving or The first section features fellows’ practicum experiences. 9 James Martin demonstrating. DEIXIS can also refer to the workings of an individual’s keen intellect, or to the means by which such The cover story highlights Alejandro Rodriguez, whose practicum Dealing With Dimensionality 22 Judith Hill 28 Milo Lin, Honorable Mention individuals, e.g. DOE CSGF fellows, are identified. produced surprising discoveries about explosive azides. In May, Speaking Many Languages Under the Hood Alex added to his CV with a Proceedings of the National Academies 13 Sarah Richardson DEIXIS is an annual publication of the Department of Energy Computational Science Graduate Fellowship (DOE of Sciences paper outlining a novel method to calculate the Practicum Sends Fellow 24 Jon Wilkening 30 Scott Clark, Honorable Mention CSGF) program that highlights the DOE CSGF fellows and Casimir force. Back to the Bench Wilkening Wades Solving Genomic Jigsaws alumni. The DOE CSGF is funded by the Office of Science Next DEIXIS revisits three alumni, including Jon Wilkening, Into Fluid Situations and the National Nuclear Security Administration’s Office of Defense Programs. a competitive swimmer whose interest in fluid mechanics is more 17 Jack Deslippe than academic. Shedding Light on 32 This issue also incorporates winners in an essay competition that Nanoscale Interactions Howes Scholars encourages fellows and alumni to write for lay readers. This year’s Living Up to a Legacy top piece, by fellow Anubhav Jain, is of interest to anyone whose laptop battery expired at the wrong time. Finally, DEIXIS reviews 10 years of the Frederick A. Howes Scholar in Computational Science award. Past recipients say the 24 35 honor set a standard for their careers — a standard 2010 honoree Directory Julianne Chung is sure to exceed. Editor Copy Editor The redesigned DEIXIS is accompanied by the launch of 35 Fellows Shelly Olsan Ron Winther deixismagazine.org, an on-line counterpart where you’ll find articles Senior Design emphasizing computational science at some of the multi-program 38 Alumni Science Writer julsdesign, inc. DOE national laboratories. Thomas R. O’Donnell We welcome your comments. DEIXIS 10 DOE CSGF ANNUAL P3 practicum profiles THE PAUSE THAT REFRESHES THE PRACTICUM IS A VITAL PART OF THE DOE CSGF — A PART THAT HAS BEEN KNOWN TO CHANGE LIVES The Department of Energy Computational DETONATION DETERMINATION Science Graduate Fellowship (DOE CSGF) supports the nation’s ALEJANDRO RODRIGUEZ Massachusetts Institute of Technology brightest science and Lawrence Livermore National Laboratory engineering students, allowing them to concentrate on learning AS IS OFTEN THE CASE in science, things didn’t go quite as planned during Alejandro Rodriguez’s practicum at Lawrence Livermore National Laboratory. and research. The work But, as it frequently is the case, too, the results were interesting anyway. Rodriguez is a recipient of a Department of Energy Computational Science Graduate of more than 200 DOE Fellowship and a doctoral candidate in condensed matter theory at the Massachusetts CSGF alumni has helped Institute of Technology (MIT). His summer 2008 practicum assignment was to help decipher the electronic structure and atomic-level chemistry when a shock hits cuprate the United States remain azide. Azides are a class of difficult-to-handle primary explosives often used to ignite more competitive in a powerful charges in mining and other applications. Lead azide, for instance, is a common Apart of car airbags. global economy. Defining the structure and chemistry could help researchers understand why heavy-metal azides are so sensitive and release such large amounts of energy. ~~~~~ “Few things are clear about the azides,” says Livermore Staff Scientist Evan Reed, who oversaw Rodriguez during the practicum. Experiments are difficult because the materials are dangerous and detonation occurs in mere picoseconds. “You can’t study reactions on that time scale with any existing experimental tools,” Left to right: THE YOUNG SCIENTISTS in the Department of Energy Reed adds. With the simulations he and Rodriguez worked on, “We’re getting the Sarah Richardson, Computational Science Graduate Fellowship devote years to their doctoral first-ever glimpse at what happens in the process of detonating these materials.” Alejandro Rodriguez, research. For at least three months, however, they break their laser-like It isn’t easy. Such simulations require modeling a cell of dozens of atoms and, more Jack Deslippe and focus to try something different. specifically, the degrees of freedom for hundreds of electrons. “You’re looking at a very, James Martin in Fellows travel to DOE national laboratories, usually during the summer, very, very large system,” Rodriguez says. Using density functional theory (DFT), a common Washington, D.C., to serve practicums. They work under lab researchers on projects that electronic structure method, may work, but modeling even a tiny time scale at the annual DOE rarely bear more than a tangential relation to their doctoral studies. The like picoseconds or nanoseconds increases the difficulty dramatically, he adds. CSGF conference. experience lets fellows apply what they know while learning new things; to Rodriguez was charged with modeling cuprate azide’s inert properties and molecular test their abilities while adding new ones; and to keep one foot in academia structure using DFT software coupled with Multiscale Shock Technique (MSST), an ab while dipping a toe into the world of the national laboratory system. initio multiscale method Reed helped develop. Rodriguez was able to predict the material’s They return to their universities with new perspectives, new energy ground state energy and other characteristics — and discovered that in detonation it and sometimes even new career paths. It’s the pause that refreshes quickly develops metallic properties. and recalibrates. P4 DEIXIS 10 DOE CSGF ANNUAL DEIXIS 10 DOE CSGF ANNUAL P5 practicum profiles Rodriguez was able to predict the material’s ground state energy and other characteristics — and discovered that in detonation it quickly develops metallic properties. ~~~~~ “That was a surprise to us and it will electromagnetism. In recent years he’s the Casimir forces on one hand,” says several methods he, McCauley, be a surprise to many others,” Rodriguez focused on electromagnetic field Rodriguez’s advisor, Steven Johnson. Joannopoulos and Johnson developed is says. “That’s a good thing. It means we fluctuations at zero temperature — That’s changed since Johnson, fellow based on the finite-difference time-domain and other people didn’t understand the otherwise known as the Casimir effect MIT professor John Joannopoulos, physics (FDTD) scheme. As the name implies, the properties as much as we thought we did.” or Casimir force. graduate student Alexander McCauley method calculates equations for electric Dutch physicist Hendrik Casimir and Rodriguez developed algorithms that and magnetic fields as they evolve in NOT SO EASY AFTER ALL predicted the force’s existence in 1948. for the first time efficiently and accurately time, independent of the frequency This visualization shows In short, Reed and Rodriguez believed The classic characterization of the force compute the Casimir force between of electromagnetic conduction. reaction products cuprate azide would be a relatively easy target describes two plates in a vacuum, facing objects with complex geometries. Now The method discretizes the partial during detonation for analysis, a belief that appears incorrect. each other just micrometers apart. Quantum “If you want to calculate some crazy shape differential equations used to calculate the of nitromethane. “It was basically metallic at a very electromagnetic field fluctuations, Casimir or some complicated periodic structure … Maxwell Green’s function