Editorial: Welcome to Structural Dynamics-A new open-access journal co-published by AIP Publishing and the American Crystallographic Association.

Abstract

Welcome to the first issue of Structural Dynamics, a new, open-access journal devoted to the science of time-evolving structures. Structural Dynamics is being launched at a key moment. Almost twenty five years ago the birth of femtosecond spectroscopy opened a new era in science by its ability to probe in “real-time” the motion of atomic nuclei in molecules of all sizes, solids, and liquids. In recent years, huge efforts have enabled experimental tools that combine the atomic resolution of time (femtoseconds) with that of length (sub-Angstrom). First, the advent of a new generation of light sources, the so-called X-ray free electron lasers (XFELs), which deliver highly coherent hard X-ray pulses of typically a few tens of femtosecond duration and with fluxes several orders of magnitude higher than the picosecond pulses of synchrotrons. Almost simultaneously, high current sources of ultrashort pulses of electrons boosted the fields of ultrafast electron diffraction and microscopy. Thus, electron and X-ray diffraction and electron microscopy are now routinely implemented with time resolutions down to tens of femtoseconds. XFELs are also opening the field for different schemes of static or time-resolved imaging thanks to their high coherence, while single shot diffraction experiments are becoming a reality. Finally, they are ideal for photon-greedy X-ray spectroscopies such as X-ray emission spectroscopy (XES) or resonant inelastic X-ray scattering (RIXS). Lab-based sources of pulsed high energy radiation are also pushing the area of structural studies to new levels, not only by methods such as X-ray diffraction, but also by studies of the electronic structure of molecular and condensed matter systems since in the end, it is the electronic structure that determines the chemical bond. Thus vacuum ultraviolet/soft X-ray lab sources using the process of high harmonic generation (HHG) are playing an increasingly important role in this respect. In addition to these new sources, there has been an impressive development of methodologies which allow new insights into the mapping of time-evolving structures of molecular and biological systems, liquids and solid materials. Photoelectron spectroscopies have recently been implemented for liquids, several new variants of X-ray spectroscopy (XES, RIXS) have now entered the time domain. A major development of the past 10–15 years has been the implementation of multidimensional spectroscopies, which are analogues of NMR in the optical domain, enabling a higher sensitivity and a higher time resolution to be achieved. These multidimensional spectroscopies in the infrared, the visible and the ultraviolet have become important structural tools due to their ability to probe correlations among different excited centers in a given system, be it a chemical, biological or condensed matter one. Efforts are even being deployed to push these multidimensional spectroscopies into the X-ray domain by means of XFELs, which are currently the only instruments that make such schemes possible. We are now on the cusp of a new “Age” in the field of structural studies. Structural Dynamics is the first journal entirely devoted to this field, with a wide range of methodologies that interrogate in “real-time” not only the evolving geometric structure, but also the underlying electronic structure of assemblies of atoms, as well as correlations between them. Because length and time scale together, the journal covers structural phenomena ranging from femtoseconds to microseconds. It is the ideal time for us to proudly launch what we are sure will become the top open access journal entirely dedicated to time-dependent structure determination. As part of promoting Structural Dynamics the first 50 papers to be published will be free – now is the time to submit your best and most exciting work before the queue is filled.