Trichromatic concept optimizes MAD experiments in synchrotron X-ray crystallography.

The trichromatic concept is a new synchrotron beamline design that optimizes MAD experiments by reducing systematic experimental errors with three-colored and coaxial synchrotron X-ray beams produced by a tandem vertical undulator and trichromator. The concept enables rapid and flexible switching of three defined wavelengths, and extends the flexibility of experimental design for MAD data collection. Thus, we can collect MAD data taking into account time series effects such as radiation damage. The data based on the trichromatic concept gave a better quality electron density map than data collected by conventional methods. It was also revealed that multicolor diffraction using dichromatic or trichromatic X-ray beams is effective in rapid MAD data collection.