Intersystem crossing (ISC), formally forbidden within nonrelativistic quantum theory, is the
mechanism by which a molecule changes its spin state. It plays an important role in the …

Nonadiabatic mixed quantum–classical (NA-MQC) dynamics methods form a class of
computational theoretical approaches in quantum chemistry tailored to investigate the time …

Understanding the properties of electronically excited states is a challenging task that
becomes increasingly important for numerous applications in chemistry, molecular physics …

A new scientific frontier opened in 2009 with the start of operations of the world's first x-ray
free-electron laser (FEL), the Linac Coherent Light Source (LCLS), at SLAC National …

The photophysics and photochemistry of DNA is of great importance due to the potential
damage of the genetic code by UV light. Quantum mechanical studies have played a key …

X-ray free-electron lasers (XFELs) and table-top sources of x-rays based upon high
harmonic generation (HHG) have revolutionized the field of ultrafast x-ray atomic and …

Fluorescent nucleoside analogues (FNAs) are structurally diverse mimics of the natural
essentially non-fluorescent nucleosides which have found numerous applications in probing …

Many photoinduced processes including photosynthesis and human vision happen in
organic molecules and involve coupled femtosecond dynamics of nuclei and electrons …

This review is focused on free-electron lasers (FELs) in the hard to soft x-ray regime. The
aim is to provide newcomers to the area with insights into: the basic physics of FELs, the …

In the field of beam physics, two frontier topics have taken center stage due to their potential
to enable new approaches to discovery in a wide swath of science. These areas are …