>I suspect that pure MIR (without anomalous) was always a fiction. I doubt that >anyone has ever used it. Heavy atoms always give >an anomalous signal
>Phil I suspect that there was a time when the anomalous signal in data sets was fictional. Before the invent of flash freezing, systematic errors due to decay and the need of scaling together many derivative data sets collected on multiple crystals could render weak anomalous signal useless. Therefore MIR was needed. Also, current hardware/software produces much better reduced data, so weak signals can become useful. Fred [32m******************************************************************************* Fred Dyda, Ph.D. Phone:301-402-4496 Laboratory of Molecular Biology Fax: 301-496-0201 DHHS/NIH/NIDDK e-mail:fred.d...@nih.gov Bldg. 5. Room 303 Bethesda, MD 20892-0560 URGENT message e-mail: 2022476...@mms.att.net Google maps coords: 39.000597, -77.102102 http://www2.niddk.nih.gov/NIDDKLabs/IntramuralFaculty/DydaFred *******************************************************************************[m