4H1P:
reference: Use of europium ions for SAD phasing of lysozyme at the Cu Kalpha wavelength., Vijayakumar B, Velmurugan D, Acta Crystallogr Sect F Struct Biol Cryst Commun. 2013 Jan 1;69(Pt 1):20-4. doi: , 10.1107/S1744309112047562. Epub 2012 Dec 25. PMID: 23295480

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