Beth

Optical excitations in nanographenes from the Bethe-Salpeter equation and time-dependent density functional theory: absorption spectra and spatial descriptors

arXiv:2510.25658v2 Announce Type: replace Abstract: The GW plus Bethe-Salpeter equation (GW-BSE) formalism is a well-established approach for calculating excitation energies and optical spectra of molecules, nanostructures, and crystalline materials. We implement GW-BSE in the CP2K code and validate the implementation for a standard organic molecular test set, obtaining excellent agreement with reference data, with a mean absolute error in excitation energies below 3 meV. We then study...

All-electron Dynamical Bethe-Salpeter Equation for Extended Systems with Atom-centered Orbital Basis Set

arXiv:2606.08350v1 Announce Type: new Abstract: Solving Bethe-Salpeter equation (BSE) for the two-particle Green's function is the most widely used approach for taking into account the particle-hole (exciton) interaction in electronic excitation in the context of the many-body theory based on Green's function. In BSE calculations, the static approximation to the screened Coulomb interaction kernel is commonly employed. However, when the excitonic character is significant as typically...

'Hwb i'r economi a'r Gymraeg' – beth fydd gwir waddol Eisteddfod yr Urdd Môn 2026?

Wrth i'r pebyll gael eu tynnu lawr ac i faes Eisteddfod yr Urdd Ynys Môn wagio, mae llawer yn gofyn yr un cwestiwn – be' fydd gwaddol yr ŵyl ar yr ynys?

Y cynnig gofal plant: 'Beth yw'r costau a'r amserlen lawn?'

'We've made £25k bagging bargains in Boots and Tesco and selling them on Amazon'

'We've made £25k bagging bargains in Boots and Tesco and selling them on Amazon' Sam Bayliss, 24, and partner Beth Jones, 25, have a lucrative side hustle A couple's side venture is raking in £25,000 annually by purchasing discounted clearance stock - including cut-price condoms - and flogging them on Amazon. Sam Bayliss, 24, and his partner Beth Jones, 25, hunt through clearance aisles in shops like Boots and Superdrug before reselling the bargains online. The duo, who each manage their own...

Agentic multi-fidelity learning of quasiparticle and excitonic properties

arXiv:2606.07836v1 Announce Type: cross Abstract: Many-body GW-Bethe-Salpeter equation calculations are essential for accurate simulations of electronic structure and optical properties in modern low-dimensional nanomaterials. However, these methods are computationally demanding and can exhibit localized numerical instabilities or convergence failures that are difficult to detect within high-throughput workflows. We introduce an agent-guided multi-fidelity framework for correcting...

Agentic multi-fidelity learning of quasiparticle and excitonic properties

arXiv:2606.07836v1 Announce Type: cross Abstract: Many-body GW-Bethe-Salpeter equation calculations are essential for accurate simulations of electronic structure and optical properties in modern low-dimensional nanomaterials. However, these methods are computationally demanding and can exhibit localized numerical instabilities or convergence failures that are difficult to detect within high-throughput workflows. We introduce an agent-guided multi-fidelity framework for correcting...

Athlete forced to travel 800 miles for meeting says £149k tribunal win could help thousands

Beth Littlewood says driving from Germany for a meeting with her no-show boss was the "final straw".

Potter finishes second in Sardinia as Yee retires

Britain's Beth Potter claims her third podium spot of the season, finishing second in the World Triathlon Series event in Alghero, Sardinia as Olympic champion Alex Yee fails to finish the men's race.

Athlete forced to travel 800 miles for meeting that boss didn't show up for wins £149,000

Beth Littlewood says driving from Germany for a meeting with her no-show boss was the "final straw".