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Our X-ray Laboratory provides access to state-of-the-art equipment and technologies, hosts a crystallography course and X-ray diffraction application training, and offers advice and technical assistance in crystal growth, data collection, and structure refinement. We welcome all Harvard affiliates as well as external users. For more information, view our brochure.

Instrumentation & Services

Small Molecule Single Crystal Diffraction

Bruker D8 VENTURE: equipped with PHOTON-100 CMOS detector, high brilliance Mo/Cu IµS microfocus X-ray sources and Oxford Cryosystream 800 series low temperature device Two APEX DUO single crystal diffractometers: equipped with APEX II CCD detector, Mo (Triumph)/Cu (IµS microfocus) X-ray sources and Oxford Cryosystream 700 series low temperature device Routine small molecule (up to 500 non-hydrogen atoms) crystal structure determinations (80-400 K), including determinations of the absolute configuration of biologically active compounds, which often do not contain atoms with larger resonant scattering signals than that of oxygen Transmission-mode (in capillaries) powder diffraction data (80-400 K) can also be collected

The Advanced Photon Source (APS) Argonne National Lab regularly awards our Lab beam time for micro-crystallography studies, high resolution charge density studies, and resonant diffraction studies. Thanks to the tunable, high-intensity X-ray beams at ChemMatCARS, our X-ray laboratory has been using advanced crystallography as an essential research tool for:

• Routine service crystallography for micro-sized crystals (less than 10 micron in two dimensions) that cannot be measured elsewhere.
• Charge density work, including ultra-high resolution, ultra-low temperature data collection, multipole refinement, and charge density analysis combined with theoretical calculations.
• Photocrystallography in exploring molecular meta-stable states. The determination of molecular motions in the crystal is based on difference maps and disorder model refinements.
• Structural studies at different temperature:  from ~10 K (Helium temperature) to 400 K.
• Resonant diffraction studies/Diffraction anomalous fine structure.
• Target guest structural determination by using crystalline sponge method.

X-ray Diffraction for Thin Film and Powder Samples

Bruker D2 PHASER: a novel desktop X-ray diffraction tool enabling fast data collection for phase identification and Rietveld refinement D8 DISCOVER with DAVINCI Design X-ray powder diffractometer: equipped with a zero/one-dimensional LynxEye detector and a two-dimensional VÅNTEC-500 detector. It is capable of performing: Qualitative and quantitative phase analysis by using Bragg-Brentano focusing with LynxEye geometry X-ray reflectivity and high-resolution X-ray diffraction analysis of thin films by using Göbel mirror/ACC2 with LynxEye geometry Stress measurement, texture analysis and non-destructive phase identification on the sample with even only 0.5 mm diameter area by using 2D X-ray diffraction (XRD2) with VÅNTEC-500 geometry

Crystal Mounting

Two Zeiss SteREO Discovery V8 microscopes: routine mounting of samples, configured with transmitted light polarization optics or AxioCam ERc5s Color CCD with AxioVision software Temperature and/or air sensitive crystals are handled using a variety of techniques; the paper of "Macromolecular cryocrystallography—methods for cooling and mounting protein crystals at cryogenic temperatures " (J. W. Pflugrath, in Methods, 2004, 33, 415-425) describes a selection of these techniques. Users can choose to supply properly mounted crystals or have the laboratory director mount the crystals.