Cryptochrome is a blue light receptor that acts as a sensor for the geomagnetic field and assists many animals in long-range navigation. The magnetoreceptor function arises from light-induced formation of a radical pair through electron transfer between a flavin cofactor (FAD) and a triad of tryptophan residues. Here, this electron transfer is investigated by quantum chemical and classical mole...

Electron spin echo envelope modulation (ESEEM) has been observed for the first time from a coupled heterospin pair of electron and nucleus in liquid solution. Previously, modulation effects in spin-echo experiments have only been described in liquid solutions for a coupled pair of homonuclear spins in nuclear magnetic resonance or a pair of resonant electron spins in electron paramagnetic reson...

We study electron-electron pairing in an one-dimensional model lattice system embedded into a three-dimensional environment. The electron pair potential is lowered by a single, localized lattice deformation. Such a deformation is related to solitons moving along the lattice. Yet the exact form and the time evolution of the lattice excitation are of secondary relevance as the electron pair is st...

A recently proposed series of corrections to the earliest JK-only functionals has considerably improved the prospects of density matrix functional theory (DMFT). Still, the most advanced of these functionals (correction C3) requires a preselection of the terms in the pair density Gamma(r(1),r(2)) involving the bonding and antibonding natural orbitals (NOs) belonging to an electron pair bond. Id...

Electron localizability indicators based on the same-spin electron pair density and the opposite-spin electron pair density are studied for correlated wavefunctions of the argon atom. Different basis sets and reference spaces are used for the multireference configuration interaction method following the complete active space calculations aiming at the understanding of the effect of local electr...

We present experimental and theoretical evidence for the potential of the two-particle spectroscopy to explore the electron-electron interaction in condensed matter. The experiment consists of a single electron impinging onto a clean surface. Two electrons are then emitted simultaneously and their momentum vectors are resolved. The measured energy and angular pair correlations within the pair c...