Can X-ray constrained Hartree–Fock wavefunctions retrieve electron correlation?

Can X-ray constrained Hartree–Fock wavefunctions retrieve electron correlation?

The X-ray constrained wavefunction (XC-WF) method proposed by Jayatilaka [Jayatilaka & Grimwood (2001) ▸, Acta Cryst. A57, 76-86] has attracted much attention because it represents a possible third way of theoretically studying the electronic structure of atoms and molecules, combining features of the more popular wavefunction- and DFT-based approaches. In its original formulation, the XC-WF te...

X-ray Correlation Spectroscopy Instrument

X-ray free-electron lasers

In a free-electron laser (FEL) the lasing medium is a high-energy beam of electrons flying with relativistic speed through a periodic magnetic field. The interaction between the synchrotron radiation that is produced and the electrons in the beam induces a periodic bunching of the electrons, greatly increasing the intensity of radiation produced at a particular wavelength. Depending only on a p...

Development of a hard X-ray delay line for X-ray photon correlation spectroscopy and jitter-free pump–probe experiments at X-ray free-electron laser sources

A hard X-ray delay line capable of splitting and delaying single X-ray pulses has been developed with the aim of performing X-ray photon correlation spectroscopy (XPCS) and X-ray pump-probe experiments at hard X-ray free-electron laser sources. The performance of the device was tested with 8.39 keV synchrotron radiation. Time delays up to 2.95 ns have been demonstrated. The feasibility of the d...

Time propagation of extreme two-electron wavefunctions

We develop a method for solving the time-dependent Schrödinger equation for the situation where two electrons interact in extreme circumstances. In particular, the method allows accurate representation of the wavefunction when several 10s or 100s of angular momenta are needed and the spatial region covers several 100s to 1000s of atomic units. The method is based on a discrete variable represen...