We're trying to solve a 50% twin crystal by experimental phasing (SAD & SIRAS) since molecular replacement hasn't worked. The crystals diffract very well in apparent space group P62 2 2. A Hg derivative shows a strong apparent anomalous signal (from half-dataset correlations etc), but we've failed to solve it so far, nor even to decide the true space group.
Has anyone out there successfully solved a 50% twin by experimental phasing? Any suggestions or tips? It would be nice to know if we are not attempting the impossible Phil Evans & Rich Suckling
