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Roadmap on Advancements of the FHI-aims Software Package
Authors:
Joseph W. Abbott,
Carlos Mera Acosta,
Alaa Akkoush,
Alberto Ambrosetti,
Viktor Atalla,
Alexej Bagrets,
Jörg Behler,
Daniel Berger,
Björn Bieniek,
Jonas Björk,
Volker Blum,
Saeed Bohloul,
Connor L. Box,
Nicholas Boyer,
Danilo Simoes Brambila,
Gabriel A. Bramley,
Kyle R. Bryenton,
María Camarasa-Gómez,
Christian Carbogno,
Fabio Caruso,
Sucismita Chutia,
Michele Ceriotti,
Gábor Csányi,
William Dawson,
Francisco A. Delesma
, et al. (177 additional authors not shown)
Abstract:
Electronic-structure theory is the foundation of the description of materials including multiscale modeling of their properties and functions. Obviously, without sufficient accuracy at the base, reliable predictions are unlikely at any level that follows. The software package FHI-aims has proven to be a game changer for accurate free-energy calculations because of its scalability, numerical precis…
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Electronic-structure theory is the foundation of the description of materials including multiscale modeling of their properties and functions. Obviously, without sufficient accuracy at the base, reliable predictions are unlikely at any level that follows. The software package FHI-aims has proven to be a game changer for accurate free-energy calculations because of its scalability, numerical precision, and its efficient handling of density functional theory (DFT) with hybrid functionals and van der Waals interactions. It treats molecules, clusters, and extended systems (solids and liquids) on an equal footing. Besides DFT, FHI-aims also includes quantum-chemistry methods, descriptions for excited states and vibrations, and calculations of various types of transport. Recent advancements address the integration of FHI-aims into an increasing number of workflows and various artificial intelligence (AI) methods. This Roadmap describes the state-of-the-art of FHI-aims and advancements that are currently ongoing or planned.
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Submitted 5 June, 2025; v1 submitted 30 April, 2025;
originally announced May 2025.
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Color of Copper/Copper oxide
Authors:
Su Jae Kim,
Seonghoon Kim,
Jegon Lee,
Youngjae Jo,
Yu-Seong Seo,
Myounghoon Lee,
Yousil Lee,
Chae Ryong Cho,
Jong-pil Kim,
Miyeon Cheon,
Jungseek Hwang,
Yong In Kim,
Young-Hoon Kim,
Young-Min Kim,
Aloysius Soon,
Myunghwan Choi,
Woo Seok Choi,
Se-Young Jeong,
Young Hee Lee
Abstract:
Stochastic inhomogeneous oxidation is an inherent characteristic of copper (Cu), often hindering color tuning and bandgap engineering of oxides. Coherent control of the interface between metal and metal oxide remains unresolved. We demonstrate coherent propagation of an oxidation front in single-crystal Cu thin film to achieve a full-color spectrum for Cu by precisely controlling its oxide-layer t…
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Stochastic inhomogeneous oxidation is an inherent characteristic of copper (Cu), often hindering color tuning and bandgap engineering of oxides. Coherent control of the interface between metal and metal oxide remains unresolved. We demonstrate coherent propagation of an oxidation front in single-crystal Cu thin film to achieve a full-color spectrum for Cu by precisely controlling its oxide-layer thickness. Grain boundary-free and atomically flat films prepared by atomic-sputtering epitaxy allow tailoring of the oxide layer with an abrupt interface via heat treatment with a suppressed temperature gradient. Color tuning of nearly full-color RGB indices is realized by precise control of oxide-layer thickness; our samples covered ~50.4% of the sRGB color space. The color of copper/copper oxide is realized by the reconstruction of the quantitative yield color from oxide pigment (complex dielectric functions of Cu2O) and light-layer interference (reflectance spectra obtained from the Fresnel equations) to produce structural color. We further demonstrate laser-oxide lithography with micron-scale linewidth and depth through local phase transformation to oxides embedded in the metal, providing spacing necessary for semiconducting transport and optoelectronics functionality.
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Submitted 15 July, 2021;
originally announced July 2021.
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The basis for design of a DSP-based coincidence spectrometer
Authors:
Pham Dinh Khang,
Nguyen Xuan Hai,
Nguyen Nhi Dien,
Pham Ngoc Tuan,
Dang Lanh,
Nguyen Duc Hoa,
Nguyen An Son
Abstract:
Coincidence technique and the coincidence measurement systems have been developed and applied for over 40 years. Most of popular coincidence measurement systems were based on analog electronics techniques such as time to amplitude conversion (TAC) or logic selecting coincidence unit. The above-mentioned systems are relatively cumbersome and complicated to use. With the strong growth of digital ele…
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Coincidence technique and the coincidence measurement systems have been developed and applied for over 40 years. Most of popular coincidence measurement systems were based on analog electronics techniques such as time to amplitude conversion (TAC) or logic selecting coincidence unit. The above-mentioned systems are relatively cumbersome and complicated to use. With the strong growth of digital electronics techniques and computational science, the coincidence measurement systems will be constructed simpler but more efficient with the sake of application. This article presents the design principle and signal processing of a simple two-channel coincidence system by a new technique called Digital Signal Processing (DSP) using Field Programmable Gate Arrays (FPGA) devices at Nuclear Research Institute (NRI), Dalat.
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Submitted 1 July, 2013;
originally announced July 2013.