Tag: crystal

Chance & Necessity: Another Look

In everyday experience, we think of chance as what governs gambling, barring schemes to harness probability in their favor. Necessity, on the other hand, brings to mind the air we breathe, food and/or water. Previously, we discussed Jacques Monod as an early explorer of the collision of probability and chance in biology. In Laws of the Game: How the Principles of Nature Govern Chance (German: Das Spiel: Naturgesetze steuern den Zufall), Manfred Eigen & Ruthild Winkler critique Jacques Monod, stating that his innovation was that the substrate of all biology is chance and accident. You may note that the subtitle of Laws of the Game states the opposite.

This gets even more subtle if you consider Johan Huizinga’s Homo Ludens: A Study of the Play Element in Culture. He emphasizes the role of playful behavior as the university that educates us in the connection between chance and necessity.

Foreword

The lay reader interested in the natural sciences is exposed to a constantly rising flood of information. He may often feel himself cast in the role of a judge before whom different authors appear like competing litigants, each of whom hopes to be found in the right. If these authors are sufficiently clever in presenting their cases, the reader may be swayed by each in turn. But then a reviewer appears on the scene and objects that each cannot be as right as the other, particularly when one author’s claims are the exact opposite of another’s. The reader has no choice but to find the reviewer right, too.

This familiar anecdote, which we have slightly adapted to suit our purposes, contains a moral: Everyone could in fact be right if each one did not insist on being the only one to be right.

Everything that happens in our world resembles a vast game in which nothing is determined in advance but the rules, and only the rules are open to objective understanding. The game itself is not identical with either its rules or with the sequence of chance happenings that determine the course of play. It is neither the one nor the other because it is both at once. It has as many aspects as we project onto it in the form of questions.

We see this game as a natural phenomenon that, in its dichotomy of chance and necessity, underlies all events. Our interpretation of games and play thus goes far beyond Huizinga’s, which considers play only in its relation to human behavior. In applying the concept of play to art, we come much closer to Adorno’s views, which clearly disagree with Huizinga‘s identification of play and art.

The considerations that gave rise to this book go back to the molecular theory of evolution worked out a few years ago. It also draws on the models developed in connection with that theory, models for simulating phenomena like equilibrium, selection, and growth, all of which are based on natural laws. Although this book makes frequent use of examples drawn from the field of biology, its scope is much broader and includes general scientific, philosophical, sociological, and aesthetic perspectives. Our main purpose is to show play in its symbolic nature and in all its metamorphoses. We also make use of its different aspects to illuminate both our scientific understanding of the world and various philosophical positions. We are aware that this brings us into conflict with those who attribute validity to one and only one aspect.

The actual writing of the book was preceded by innumerable talks and discussions with friends and colleagues during our Engadin winter seminars, on hikes and ski tours in the mountains, and, occasionally, over a bottle of wine. We first thought a dialogue would be the appropriate form for our exchange of ideas, but we soon abandoned this concept. The classical dialogues are without exception artificially constructed. Simplicio and Salviati, for example, are both mouthpieces for Galileo. We finally decided that we would both take turns going over all the material point by point. We have, of course, ventured into areas in which we are only dilettantes. We hope the reader will forgive us this in the light of our efforts to uncover parallels and so to emphasize the unity of nature and mind.

We do not want to go any further into the substance of the book here than is necessary to make clear why we chose the title we did. Similarly, the introductions to the individual chapters are meant to lead the reader into the material treated, not to summarize it.

Chance and law (or principles) are the basic elements of games. The subtitle of the book suggests the interaction between them. And here we should add that it is the consequences of chance that are subject to regulation. Only if there is a large number of individual events does the element of chance come under the control of statistical law. This law is at work, for instance, when chance fluctuations undergo self-regulation in equilibrium or when they are amplified in the evolutionary process. The origin of the genetic code, the development of languages by which we transmit our thoughts, the intellectual play of artistic imagination are all based on the same fundamental principles of evolution, even though the results of individual games are determined by the caprice and variability of chance.

The manifestations of the game that matter plays in time and space and the effects this game has on human beings are the themes of the central chapters in the book. Much as we may agree with Jacques Monod in his view of molecular biology, we differ from him greatly in the conclusions he draws from it for mankind and society. We see Monod’s demand for an “existential attitude toward life and society” as an animistic inflation of the role of “chance.” Such a demand neglects the complementary role played by natural law. Criticism of the dialectical overemphasis on “necessity”—a criticism we find fully justified—should not move us to deny completely its obvious infiuence.

We are in complete agreement with Monod’s statement that ethics and knowledge cannot be divorced from each other. For us, however, this view does not condemn the great religions but rather sets them a new task. As we have occasion to point out in the present work, the natural sciences yield no proof of God’s existence, but neither do they claim that men “can do without faith in God.”

The unity of nature is expressed more in the laws governing the relationships between structures than in the structures themselves. Taking this “motto” as a point of departure for Part IV, we examine a number of problems that have recently come more and more under the purview of the natural sciences and that are still far from being solved. In these considerations, we are mainly concerned with the mechanisms of cognizance. In terms of the elementary processes involved, these mechanisms always amount to a falsification in Karl Popper’s sense. Still, we cannot fully accept the views of this great epistemological logician, particularly when he claims: “There is no induction.” Good enough! But there are different mechanisms of falsification that vary in their degree of inductive adaptation.

One of our main concerns in this book lies at the heart of Part III. There we raise the still unsolved question of the hubris of human knowledge. Friedrich Dürrenmatt’s categorical imperative “What concerns all can only be worked out by all” is as relevant for the physicist whose knowledge can unleash the forces of nature as it is for the biologist who is now in a position to manipulate genetic material and influence psychic behavior with drugs. And our appeal here is also directed at the economist and the politician, who have the task of creating, maintaining, and protecting the conditions necessary for a worthwhile human existence.

Pessimistic predictions based on simple extrapolation are widespread today. We will not be able to solve the problem of limited resources by frugality alone. A raw material that will be used up in about fifty years at present rates of consumption might last a hundred years if we cut down on its use. (Such a reduction might, of course, threaten the stability of our economy.) In other words, the catastrophe could be delayed for another fifty years. Would it not be more sensible to concentrate on ensuring unlimited resources, perhaps by reusing our raw materials in a recycling economy and by developing sufficiently productive sources of energy? However we solve this problem, the practicability of our solution will depend on stopping population growth, perhaps even on reducing the world’s population.

We must be clear about one thing: The human being is not a fluke of nature, nor does nature automatically guarantee his survival. The human being is one player in a huge game, the outcome of which is, for him, uncertain. He has to make full use of his capabilities to hold his own as a player and not become a plaything of chance.

Manfred Eigen / Ruthild Winkler-Oswatitsch
Göttingen, September 1975

ONE

The Taming of Chance

Research in physics has shown beyond the shadow of a doubt that in the overwhelming majority of phenomena whose regularity and invariability have led to the formulation of the postulate of causality, the common element underlying the consistency observed is chance.

Erwin Schrödinger, “What Is a Natural Law?” (Inaugural Address delivered at the University of Zurich, December 1922)

1

The Origin of Play

Play is a natural phenomenon that has guided the course of the world from its beginnings. It is evident in the shaping of matter, in the organization of matter into living structures, and in the social behavior of human beings.

The history of play goes back to the beginnings of time. The energy released in the “big bang” set everything in motion, set matter whirling in a maelstrom of activity that would never cease. The forces of order sought to bring this process under control, to tame chance. The result was not the rigid order of a crystal but the order of life. From the outset, chance has been the essential counterpart of the ordering forces.

Chance and rules are the elements that underlie games and play. Play began among the elementary particles, atoms, and molecules, and now our brain cells carry it on. Human beings did not invent play, but it is “play and only play that makes man complete.”1

All our capabilities arise from play. First, there is the play of limbs and muscles. The aimless grasping and kicking of an infant develop into carefully coordinated movements. Then there is the play of our senses. Playful curiosity sends us in search of profound knowledge. From play with colors, shapes, and sounds emerge immortal works of art. The first expressions of love take the form of play: the secret exchange of glances, dancing, the interplay of thoughts and emotions, the yielding of partners to each other. In Sanskrit, the union of lovers is called kridaratnam, “the jewel of games.”2

Every game has its rules that set it apart from the surrounding world of reality and establish its own standards of value. Anyone who wants to “play” has to follow those rules. In parlor games, rules established before the game begins determine the course the game will take and define the scale of values by which it is played. But the effects of a chance occurrence can change the constellation of the game and set it running in a totally new direction. This is how life initiated its first games, and this is how our thoughts and ideas continue to play those games.

From the terrifying realm of elemental forces and the holy realm of laws arises the aesthetic impulse, which creates a third, carefree realm. This is the realm of play and appearance. In it, man is freed from the bonds of all circumstance and liberated from compulsion, moral as well as physical.1

It is our intention in this book to trace the interplay of chance and law that has come down to us from the farthest reaches of time and found its most perfect expression in the inexhaustible creativity of our ideas. We hope to translate Hermann Hesse’s symbol of the glass bead game back into reality. Hesse described this game as one that incorporated all the values of our culture.

All the insights, noble thoughts, and works of art that the human race has produced in its creative eras, all that subsequent periods of scholarly study have reduced to concepts and converted into intellectual property—on all this immense body of intellectual values the Glass Bead Game player plays like the organist on an organ. And this organ has attained an almost unimaginable perfection; its manuals and pedals range over the entire intellectual cosmos; its stops are almost beyond number. Theoretically this instrument is capable of reproducing in the Game the entire intellectual content of the universe.3

There is something mysterious about glass beads. The reflection and refraction of light make them glow, and as we explore the idea of play in this book, Hesse’s glass beads will take on a new life. Part of their symbolic significance derives from the fact that they can exemplify the constant transformations and metamorphoses we observe all around us: atoms evolve into crystals, molecules into genes, living cells into cognitive beings, letters into words, notes into harmonies. The course the bead game takes is determined by the roll of the dice, yet at the same time it is also influenced by the rules of the game, just as chance in nature is subject to the laws of physics. The dice and the rules of the game these are our symbols for chance and natural law.

List of References

  1. Schiller, Friedrich von, “Über die ästhetische Erziehung des Menschen (On the Aesthetic Education of Mankind),” in a series of letters from the years 1793-94, printed in his Philosophical and Critical Writings (many eds.).
  2. Huizinga, Johan, Homo Ludens: A Study of the Play Element in Culture. Boston: Beacon Press, 1955.
  3. Hesse, Hermann, The Glass Bead Game: Magister Ludi. New York: Holt, Rinehart & Winston, 1969.
Manfred Eigen & Ruthild Winkler. Laws of the Game: How the Principles of Nature Govern Chance. Translated by Rita & Robert Kimber, Princeton University Press, 1993, pp. xi-5.

Theodor Adorno, a Marxist theoretician, believed the filter before any interpretation of the world was ever-present advertising and, by extension, capitalism. While Adorno thinks of capitalism as destiny, Yeats came to realize that “accident is destiny” (as we previously discussed). Amid these infinitely debatable opinions, the world is often a perplexity machine that may not be described by a single view.

World-Watching: Science First Release, 10 July 2025

[from Science]

Accepted papers posted online prior to journal publication.

NASA Earth Science Division provides key data

by Dylan B. Millet, Belay B. Demoz, et al.

In May, the US administration proposed budget cuts to NASA, including a more than 50% decrease in funding for the agency’s Earth Science Division (ESD), the mission of which is to gather knowledge about Earth through space-based observation and other tools. The budget cuts proposed for ESD would cancel crucial satellites that observe Earth and its atmosphere, gut US science and engineering expertise, and potentially lead to the closure of NASA research centers. As former members of the recently dissolved NASA Earth Science Advisory Committee, an all-volunteer, independent body chartered to advise ESD, we warn that these actions would come at a profound cost to US society and scientific leadership.

[read more]

Spin-filter tunneling detection of antiferromagnetic resonance with electrically tunable damping

by Thow Min Jerald Cham, Daniel G. Chica, et al.

Antiferromagnetic spintronics offers the potential for higher-frequency operations and improved insensitivity to magnetic fields compared to ferromagnetic spintronics. However, previous electrical techniques to detect antiferromagnetic dynamics have utilized large, millimeter-scale bulk crystals. Here we demonstrate direct electrical detection of antiferromagnetic resonance in structures on the few-micrometer scale using spin-filter tunneling in PtTe2/bilayer CrSBr/graphite junctions in which the tunnel barrier is the van der Waals antiferromagnet CrSBr. This sample geometry allows not only efficient detection, but also electrical control of the antiferromagnetic resonance through spin-orbit torque from the PtTe2 electrode. The ability to efficiently detect and control antiferromagnetic resonance enables detailed studies of the physics governing these high-frequency dynamics.

[read more]

Scalable emulation of protein equilibrium ensembles with generative deep learning

by Sarah Lewis, Tim Hempel, et al.

Following the sequence and structure revolutions, predicting functionally relevant protein structure changes at scale remains an outstanding challenge. We introduce BioEmu, a deep learning system that emulates protein equilibrium ensembles by generating thousands of statistically independent structures per hour on a single GPU. BioEmu integrates over 200 milliseconds of molecular dynamics (MD) simulations, static structures and experimental protein stabilities using novel training algorithms. It captures diverse functional motions—including cryptic pocket formation, local unfolding, and domain rearrangements—and predicts relative free energies with 1 kcal/mol accuracy compared to millisecond-scale MD and experimental data. BioEmu provides mechanistic insights by jointly modeling structural ensembles and thermodynamic properties. This approach amortizes the cost of MD and experimental data generation, demonstrating a scalable path toward understanding and designing protein function.

[read more]

Negative capacitance overcomes Schottky-gate limits in GaN high-electron-mobility transistors

by Asir Intisar Khan, Jeong-Kyu Kim, et al.

For high-electron-mobility transistors based on two-dimensional electron gas (2DEG) within a quantum well, such as those based on AlGaN/GaN heterostructure, a Schottky-gate is used to maximize the amount of charge that can be induced and thereby the current that can be achieved. However, the Schottky-gate also leads to very high leakage current through the gate electrode. Adding a conventional dielectric layer between the nitride layers and gate metal can reduce leakage; but this comes at the price of a reduced drain current. Here, we used a ferroic HfO2 – ZrO2 bilayer as the gate dielectric and achieved a simultaneous increase in the ON current and decrease in the leakage current, a combination otherwise not attainable with conventional dielectrics. This approach surpasses the conventional limits of Schottky GaN transistors and provides a new pathway to improve performance in transistors based on 2DEG.

[read more]

Science-Watching: New Insights into Polyamorphism Could Influence How Drugs Are Formulated

[from the Royal Society of Chemistry’s Chemistry World, by Patrick de Jongh]

Results from a study combining experiments and simulations could overturn the assumption that amorphous forms of the same compound have the same molecular arrangement. The team behind the work claims to have prepared three amorphous forms of the diuretic drug hydrochlorothiazide and determined that they have distinct properties and distinct types of disorder. ‘If polyamorphism is proved in the future to be a universal—or at least not a very rare—phenomenon, then the pharmaceutical industry will need to make screens for polyamorphism and this will also be an opportunity for patenting,’ comments Inês Martins, from the University of Copenhagen in Denmark, who led the work with Thomas Rades.

Crystalline active pharmaceutical ingredients (APIs) often suffer from poor solubility. A common strategy to circumvent this problem is converting APIs into their amorphous form. This has been demonstrated for various APIs, including hydrochlorothiazide. However, the physical properties of polyamorphs are dependent on how they were prepared. Given there are no straightforward techniques to study how molecules interact and organise themselves in amorphous materials, the area is poorly understood.

Nevertheless, a team surrounding Rades and Martins set out to identify how amorphous forms of the same API, presenting different physicochemical properties, differ from each other. They decided to study hydrochlorothiazide as it was previously shown to have polyamorphs with glass transition temperatures above room temperature, which facilitates the preparation, isolation and analysis of its different polyamorphs. Starting from crystalline hydrochlorothiazide, they produced three polyamorphs: polyamorph I via spray-drying, polyamorph II via quench-cooling and polyamorph III by ball-milling. Thermal analysis revealed a significantly lower glass-transition temperature for polyamorph I (88.7°C), whereas polyamorphs II and III had similar glass-transition temperatures (117.5°C and 119.7°C, respectively). The polyamorphs also demonstrated very different shelf-life stabilities against crystallisation.

Subsequently, they studied polyamorphic interconversions by submitting the polyamorphs to the preparation conditions used for other polyamorphs. For example, polyamorph I (obtained by spray-drying) was subjected to quench–cooling or ball-milling. Identifying temperature as a critical parameter, they observed that polyamorph II could be obtained from polyamorphs I and III, but the reverse pathway was not possible. Meanwhile, they observed polyamorph I and polyamorph III interconvert. These results demonstrate polyamorph II is the most stable amorphous form.

Source: © Thomas Rades/University of Copenhagen
Researchers used a variety of techniques to elucidate the different polyamorphs that can be produced from crystalline hydrochlorothiazide and the polyamorphic interconversions that occur when a specific amorphous form is submitted to temperature or milling treatments

‘The problem out of the gate with polyamorphism as a concept is how to tell the difference between a well-defined metastable amorphous structure and an unrelaxed one that simply results from kinetically trapped defects introduced during processing. This is hard to define since the amorphous structure is statistical in any case,’ comments Simon Billinge, who studies the structure of disordered materials at Columbia University in the US. ‘They process the samples very differently. We know—from our own work—that this results in amorphous phases with very different stabilities against recrystallisation, for example, but is this polyamorphism? On the other hand, they find that the pair distribution functions of each of their “forms” are identical. There is no experimental evidence for a distinct structure. Taken together, the results do little to advance my understanding of polyamorphism.’

Distinct dihedral angle distributions

To get further information on how the polyamorphs are different on a molecular level, Martins and Rades turned to molecular dynamics simulations, comparing the dihedral angles around the sulfonamide groups in polyamorphs I and II. ‘Polyamorph I, which has a large number of the molecules with a dihedral angle similar to the one reported for crystalline hydrochlorothiazide, has a lower physical stability and faster structural relaxation time than polyamorph II, which has a broader dihedral angle distribution. Our findings indicate that a broader dihedral angle distribution seems to contribute to a better physical stability and slower structural relaxation,’ says Martins. They therefore hypothesise that having half the molecules with a conformation closer to crystalline hydrochlorothiazide and half of the molecules with a different conformation could help in establishing specific molecular arrangements that would favour the stability of the amorphous form.

The team also says the simulations corroborated its experimental results that polyamorph I can transform into polyamorph II, while the opposite conversion did not take place.

However, Billinge does not believe the computational studies provide conclusive evidence: ‘There is a detailed molecular dynamics analysis where different annealing conditions in the simulations give some slightly different statistics on the molecular conformations, but despite their claim, the resulting computed pair distribution functions do not look like the measured ones, so we have no way of knowing if the molecular dynamics is capturing what is happening in the real material. For amorphous materials, it is very difficult to equilibrate them in a molecular dynamics simulation, so you will be looking at artefacts of how the ensemble was created. Any claims to have found polyamorphism from molecular dynamics simulations by themselves are therefore questionable.’

Rades says their results can change the field of pharmaceutics: ‘We expect that other drug molecules may exhibit polyamorphism and the question would be which structural parameters would be different. In the case of hydrochlorothiazide, the dihedral angle distribution was found to be a parameter contributing for the formation of different polyamorphs. In other drugs, maybe the dihedral angle distribution (molecular conformations) could be different as well, but also maybe the type of intermolecular interactions can play a more important role in the formation of polyamorphs.’

The team now hope the pharmaceutical industry will look at amorphous systems differently and not assume that all amorphous forms of the same compound are the same. ‘Knowing this and considering that a certain polyamorph will have better physical stability, solubility or dissolution properties than another polyamorph, this will be an opportunity for the pharmaceutical industry to prepare tablets of a drug where the dose could be lower than tablets containing the crystalline form,’ concludes Rades.

New Ultrathin Capacitor Could Enable Energy-Efficient Microchips

Scientists turn century-old material into a thin film for next-gen memory and logic devices

[from Berkeley Lab, by Rachel Berkowitz]

Electron microscope images show the precise atom-by-atom structure of a barium titanate (BaTiO3) thin film sandwiched between layers of strontium ruthenate (SrRuO3) metal to make a tiny capacitor. (Credit: Lane Martin/Berkeley Lab)

The silicon-based computer chips that power our modern devices require vast amounts of energy to operate. Despite ever-improving computing efficiency, information technology is projected to consume around 25% of all primary energy produced by 2030. Researchers in the microelectronics and materials sciences communities are seeking ways to sustainably manage the global need for computing power.

The holy grail for reducing this digital demand is to develop microelectronics that operate at much lower voltages, which would require less energy and is a primary goal of efforts to move beyond today’s state-of-the-art CMOS (complementary metal–oxide semiconductor) devices.

Non-silicon materials with enticing properties for memory and logic devices exist; but their common bulk form still requires large voltages to manipulate, making them incompatible with modern electronics. Designing thin-film alternatives that not only perform well at low operating voltages but can also be packed into microelectronic devices remains a challenge.

Now, a team of researchers at Lawrence Berkeley National Laboratory (Berkeley Lab) and UC Berkeley have identified one energy-efficient route—by synthesizing a thin-layer version of a well-known material whose properties are exactly what’s needed for next-generation devices.

First discovered more than 80 years ago, barium titanate (BaTiO3) found use in various capacitors for electronic circuits, ultrasonic generators, transducers, and even sonar.

Crystals of the material respond quickly to a small electric field, flip-flopping the orientation of the charged atoms that make up the material in a reversible but permanent manner even if the applied field is removed. This provides a way to switch between the proverbial “0” and “1” states in logic and memory storage devices—but still requires voltages larger than 1,000 millivolts (mV) for doing so.

Seeking to harness these properties for use in microchips, the Berkeley Lab-led team developed a pathway for creating films of BaTiO3 just 25 nanometers thin—less than a thousandth of a human hair’s width—whose orientation of charged atoms, or polarization, switches as quickly and efficiently as in the bulk version.

“We’ve known about BaTiO3 for the better part of a century and we’ve known how to make thin films of this material for over 40 years. But until now, nobody could make a film that could get close to the structure or performance that could be achieved in bulk,” said Lane Martin, a faculty scientist in the Materials Sciences Division (MSD) at Berkeley Lab and professor of materials science and engineering at UC Berkeley who led the work.

Historically, synthesis attempts have resulted in films that contain higher concentrations of “defects”—points where the structure differs from an idealized version of the material—as compared to bulk versions. Such a high concentration of defects negatively impacts the performance of thin films. Martin and colleagues developed an approach to growing the films that limits those defects. The findings were published in the journal Nature Materials.

To understand what it takes to produce the best, low-defect BaTiO3 thin films, the researchers turned to a process called pulsed-laser deposition. Firing a powerful beam of an ultraviolet laser light onto a ceramic target of BaTiO3 causes the material to transform into a plasma, which then transmits atoms from the target onto a surface to grow the film. “It’s a versatile tool where we can tweak a lot of knobs in the film’s growth and see which are most important for controlling the properties,” said Martin.

Martin and his colleagues showed that their method could achieve precise control over the deposited film’s structure, chemistry, thickness, and interfaces with metal electrodes. By chopping each deposited sample in half and looking at its structure atom by atom using tools at the National Center for Electron Microscopy at Berkeley Lab’s Molecular Foundry, the researchers revealed a version that precisely mimicked an extremely thin slice of the bulk.

“It’s fun to think that we can take these classic materials that we thought we knew everything about, and flip them on their head with new approaches to making and characterizing them,” said Martin.

Finally, by placing a film of BaTiO3 in between two metal layers, Martin and his team created tiny capacitors—the electronic components that rapidly store and release energy in a circuit. Applying voltages of 100 mV or less and measuring the current that emerges showed that the film’s polarization switched within two billionths of a second and could potentially be faster—competitive with what it takes for today’s computers to access memory or perform calculations.

The work follows the bigger goal of creating materials with small switching voltages, and examining how interfaces with the metal components necessary for devices impact such materials. “This is a good early victory in our pursuit of low-power electronics that go beyond what is possible with silicon-based electronics today,” said Martin.

“Unlike our new devices, the capacitors used in chips today don’t hold their data unless you keep applying a voltage,” said Martin. And current technologies generally work at 500 to 600 mV, while a thin film version could work at 50 to 100 mV or less. Together, these measurements demonstrate a successful optimization of voltage and polarization robustness—which tend to be a trade-off, especially in thin materials.

Next, the team plans to shrink the material down even thinner to make it compatible with real devices in computers and study how it behaves at those tiny dimensions. At the same time, they will work with collaborators at companies such as Intel Corp. to test the feasibility in first-generation electronic devices. “If you could make each logic operation in a computer a million times more efficient, think how much energy you save. That’s why we’re doing this,” said Martin.

This research was supported by the U.S. Department of Energy (DOE) Office of Science. The Molecular Foundry is a DOE Office of Science user facility at Berkeley Lab.