DESCRIPTION: Gordon Research Conference (GRC) on Electron Distribution and Chemical Bonding. Dynamics and Densities. Mount Holyoke College, South Hadley, MA, USA, 1-6 July 2007. This GRC is traditionally aimed at presenting a forum for discussion on the interplay between theory and experiment when measuring and calculating properties related to electron distribution and the making/breaking of chemical bonds. A large emphasis is also devoted to the fundamental aspects of the chemical bond and how its very nature determines the observed chemical properties and reactivity. With the advent of time-resolved (TR) spectroscopy and crystallographic studies and, especially, in 5-10 years, of the X-ray Free Electron Lasers (XFEL) international facilities, the scenario of structural biology is going to amazingly change. XFEL will set the fourth generation X-ray sources, with pulses about ten orders of magnitude more brilliant and approximately three orders of magnitude shorter, a few femtoseconds, than those provided by synchrotrons - the present third generation sources. XFEL will enable us to obtain single molecule X-ray diffraction imaging and thus a detailed structural analysis of those biologic macromolecules or macromolecular assemblies which are difficult or even impossible to crystallize. A crystallography without crystals. A 3D structure at close to atomic resolution is a key-step for all investigations concerning structure- function relationship and about 30% of the proteins encoded in the humane genome are hardly crystallisable membrane proteins. They are also the target for about 70% of all known drugs. A wealth of new and of accurate information on the structural details and on the structural evolution of biologic complex systems along reactions mechanisms which are at the basis of their functionalities will so become progressively available. Four out of the nine sessions of this GRC are designed to trigger the attention of the charge density (CD) and chemical bond community, especially of younger people, towards the new scientific era this community will be soon asked to take part of. A community, which is so expert in the finest details of chemical bond and chemical reactivity characterization, understanding and modeling can not be set apart from the scientific progress fostered by the increasing importance of TR studies and the advent of XFEL. Instead, it may greatly and originally contribute to such a progress. The present pioneering TR spectroscopic and diffraction studies on macromolecules and chemical reactions will be discussed for they are laying the foundations for similar studies on increasingly complex cases at the developing XFEL sources. They also show how TR diffraction need to be integrated with novel TR spectroscopic techniques to enhance our insight on the structure/function relationships in biological systems. An overview of the many fundamental scientific problems to be afforded with XFEL will be given by speakers coming from the sites where these facilities will be eventually set up. Charge density protein databases will be discusses as a way to extend the experimental CD methodology to biocrystallography. If information on structure and structural evolution yields a picture of a macromolecule and of how it evolves with time, knowledge of its CD will provide a clue to understand why it is so evolving. The scenario of structural biology is going to amazingly change with the recent progresses in time- resolved spectroscopy and crystallography and, especially, with the advent in 5-10 years from now, of the X-ray Free Electron Lasers international facilities. A crystallography without crystals will become feasible, which represents a fundamental progress considering that about 30% of the proteins encoded in the humane genome are hardly crystallisable membrane proteins and that these proteins are the target for about 70% of all known drugs. This new structural information, along with the progresses currently being made in the charge density protein databases will allow to extend the experimental CD methodology to biocrystallography; information on structure and structural evolution yields a picture of a macromolecule and of how it evolves with time, knowledge of its charge density CD will provide a clue to understand why it is so evolving. [unreadable] [unreadable] [unreadable]