Structural Molecular Biology

Illuminating Biological Structures at the Atomic and Molecular Levels

Click here to learn about capabilities available at other BER Structural Biology and Imaging Resources.

X-ray Spectroscopy & Imaging

SSRL has five hard X-ray Spectroscopy beam lines and three Microfocus Imaging beam lines dedicated or shared for biological, biomedical and bioenergy research funded by the NIH and DOE-BER. The SMB group supports and develops technical instrumentation and theoretical methods for state-of-the-art tender and hard X-ray spectroscopy and EXAFS studies on metalloproteins, cofactors and metals in biology. The SMB group has also contributed to the development of a wiggler end-station beam line and facilities for X-ray emission and Raman spectroscopy, HERFD and RIXS measurements on biological and biomimetic systems. A holistic imaging methodology combining spectroscopy and X-ray fluorescence has been developed on three beam lines encompassing μm-cm scale specimen over the tender & hard X-ray regime integrating hardware and software for seamless measurement across the stations.

X-ray Absorption Spectroscopy


  • Low-temperature XAS
  • Single-crystal XAS

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Advanced Spectroscopy


  • RIXS
  • XES
  • XRS

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X-ray Fluorescence Imaging


  • XRF Mapping
  • Micro-XANES
  • Micro-EXAFS imaging

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The SMB group maintains and operates standard and specialized in-hutch instrumentation for a variety of research programs. These include; cryostats for low-temperature measurements, detector systems serving dilute and concentrated samples and specialized instrumentation for tender-energy and single-crystal XAS measurements. Experimental details about beam lines and information about their specific capabilities are listed under each beam lines technical page.

X-ray Absorption Spectroscopy
Advanced Spectroscopy
X-ray Fluorescence Imaging

Data Collection

WebXAS is the SSRL X-ray Absorption Spectroscopy in-browser data acquisition program. It is designed to allow quick and easy XAS experimental setup and data collection, and to make optimal use of available beam time. It has many facilities, including the ability to run remote access, all of which are described in on-line documentation. Click here to see the WebXAS Help Guide. WebGe, included in WebXAS, is used to interface with the multi-element fluorescence detectors at both BL7-3 (30-element Ge detector) and BL9-3 (100-element Ge detector).

Data Analysis


The data analysis packages EXAFSPAK and SIXPACK are available free of charge. Both are currently installed on the XAS beamline computers. Windows and a variety of Unix versions are currently available. These, and the manual for EXAFSPAK, can be obtained here. The manual for SIXPACK can be obtained here.

The MicroAnalysis Toolkit

The data analysis package, The MicroAnalysis Toolkit, is available free of charge for visualizing and processing X-ray Fluorescence imaging data. The MicroAnalysis Toolkit is available at all of the XRF imaging beamlines, and staff are well versed in assisting users with this software. Instructions for The MicroAnalysis Toolkit download. Basic processing and help for various functions can be found here.

Other Programs



Some useful utilities to aid user measurements are provided below.

Eulerian to Kappa Geometry Calculator

Ion Chamber Photon Flux Calculator