Ab initio quality neural-network potential for sodium

An interatomic potential for high-pressure high-temperature (HPHT) crystalline and liquid phases of sodium is created using a neural-network (NN) representation of the ab initio potential energy surface. It is demonstrated that the NN potential provides an ab initio quality description of multiple properties of liquid sodium and bcc, fcc, cI16 crystal phases in the P-T region up to 120 GPa and 1200 K. The unique combination of computational efficiency of the NN potential and its ability to reproduce quantitatively experimental properties of sodium in the wide P-T range enables molecular dynamics simulations of physicochemical processes in HPHT sodium of unprecedented quality.Comment: 8 pages, 11 figures, 2 table

The ASDEX Upgrade UTDC and DIO cards - A family of PCI/cPCI devices for real-time DAQ under Solaris

A Universal Time to Digital Converter (UTDC) and a Digital I/O (DIO) card have been built to purpose for the new ASDEX Upgrade control system, the Thomson Scattering diagnostic, a renovation of the Magnetic Measurement, and a couple of other diagnostics requiring renewed timing or real-time features. The salient features of these cards will be presented, and we will show how synergy in hardware and software development could be achieved. Examples of real-life applications in diagnostics will be given. Measurements of the real-time behaviour of those diagnostics show a low jitter of the Solaris operating system and highly reliable function under moderate real-time conditions. Future extension of the usability of this family of cards will be described as an outlook. Topic: Diagnostic Control and Data Acquisitio

Coulomb parameters and photoemission for the molecular metal TTF-TCNQ

We employ density-functional theory to calculate realistic parameters for an extended Hubbard model of the molecular metal TTF-TCNQ. Considering both intra- and intermolecular screening in the crystal, we find significant longer-range Coulomb interactions along the molecular stacks, as well as inter-stack coupling. We show that the long-range Coulomb term of the extended Hubbard model leads to a broadening of the spectral density, likely resolving the problems with the interpretation of photoemission experiments using a simple Hubbard model only.Comment: 4 pages, 2 figure

Cold spray deposition of metallic-UHTC composites

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