Publications

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

We honor Professor Hartmut Karl Lichtenthaler, a versatile pioneer of photosynthesis research, plant physiology, isoprenoid biochemistry, and stress physiology of plants, for his groundbreaking and creative contributions to plant science. His innovative research on the chemical composition, ultrastructure, and function of chloroplasts and his detection of the major methylerythritol 4-phosphate (MEP) isoprenoid biosynthetic pathway in plants is key to our current understanding of the physiology and biochemistry of photosynthesis systems. His ingenious use of the powerful laser-induced chlorophyll <i>a</i> fluorescence imaging has helped us better understand the stress response processes in plant leaves. In this tribute, we present a summary of Lichtenthaler's career, significant scientific contributions, editorial engagement, promotion of international cooperation, many honors, and awards, as well as his devotion to hiking and mountaineering.

Since the 1960s, the paddlewheel effect has been proposed as a way to enhance lithium-ion diffusion in inorganic materials by using rotor-like anion groups to assist lithium-ion movement( 1 – 5 ). However, so far the physical mechanism behind how anion-group dynamics affect lithium-ion diffusion has not been clearly understood. In this talk, we clearly define various types of rotational motions of anion-groups. Based on such definition, we detect and differentiate such distinct anion-group rotational motions throughout a total of 10’s of ns ab-initio molecular dynamics trajectories. By performing rigorous statistical analysis of various rotational events as well as lithium-ion diffusion events, we reveal how each type of anion rotational motions are related to lithium-ion diffusion. Our research has finally resolved the ongoing debate about the existence of the paddlewheel effect and provide a clear physical understanding of how anion-group rotations are related to fast ionic diffusion in inorganic materials. L. Karlsson, R. L. McGreevy, Mechanisms of ionic conduction in Li2SO4 and LiNaSO4: Paddle wheel or percolation? Solid State Ionics . 76, 301–308 (1995). A. Kvist, A. Lundén, Electrical Conductivity of Solid and Molten Lithium Sulfate. Zeitschrift Für Naturforschung . 20, 235–238 (1965). Z. Zhang, L. F. Nazar, Exploiting the paddle-wheel mechanism for the design of fast ion conductors. Nat Rev Mater , 1–17 (2022). J. G. Smith, D. J. Siegel, Low-temperature paddlewheel effect in glassy solid electrolytes. Nat Commun . 11, 1483 (2020). M. Jansen, Volume Effect or Paddle‐Wheel Mechanism—Fast Alkali‐Metal Ionic Conduction in Solids with Rotationally Disordered Complex Anions. Angewandte Chemie Int Ed Engl . 30, 1547–1558 (1991).

We study the response of random singlet quantum critical points to local\nperturbations. Despite being insulating, these systems are dramatically\naffected by a local cut in the system, so that the overlap $G=\\left|\\langle\n\\Psi_B |\\Psi_A \\rangle\\right|$ of the groundstate wave functions with and\nwithout a cut vanishes algebraically in the thermodynamic limit. We analyze\nthis Anderson orthogonality catastrophe in detail using a real-space\nrenormalization group approach. We show that both the typical value of the\noverlap G and the disorder average of $G^\\alpha$ with $\\alpha&gt;0$ decay as\npower-laws of the system size. In particular, the disorder average of\n$G^\\alpha$ shows a "multifractal" behavior, with a non-trivial limit $\\alpha\n\\to \\infty$ that is dominated by rare events. We also discuss the case of more\ngeneric local perturbations and generalize these results to local quantum\nquenches.\n

Machine learning (ML) is transforming all areas of science. The complex and time-consuming calculations in molecular simulations are particularly suitable for an ML revolution and have already been profoundly affected by the application of existing ML ...Read More

We have extended the work of Van Dyk [AJ, 103, 1788 (1992)] on the association of supernovae with massive star formation regions, as traced by giant H II regions, in late-type galaxies. In this paper, we concentrate only on supernovae arising from massive progenitors, Type Ib/c and Type II, using ground-based CCD Hα images. We improve upon earlier studies by increasing the supernova sample, by including only spectroscopically classified supernovae, and by obtaining more accurate astrometry of the supernovae and their environments. We find that the degree of association of both supernova types with H II regions in their parent galaxies is not significantly different, implying that both types arise from essentially the same range of stellar masses. From consideration of the statistics in this paper, including the Hα luminosities of the H II regions with which supernovae are associated, we can exclude the Wolf-Rayet star progenitor model for most Type Ib/c supernovae. Instead, the progenitors of Type Ib/c supernovae are probably in relatively close binary systems, rather than single stars or stars in wide binaries (possible progenitor systems for Type Il supernovae); interaction with a companion star can severely deplete the hydrogen envelope prior to explosion.