That's because they are Harker peaks which for good reasons are unsuitable as translation search vectors. The Patterson function is well explained in many of the standard crystallographic texts (e.g. Giacovazzo's book that I already recommended) and maybe you need to read these before asking your next question!
George On 12/14/2012 10:05 AM, Wei Feng wrote: > Dear professor George Sheldrick, > I am so sorry to bother you again! > From the shelxc_fa.lst file, we can find that the Patterson peaks will > be selected only when the 'Mult' equal to 1.0000. >> >>> shelxc_fa.lst: >>> Patterson (* indicates vector selected for search) >>> >>> X Y Z Height Mult Length >>> >>> 0.0000 0.0000 0.0000 999.9 0.0435 0.00 >>> 0.0553 0.0553 0.0159 43.8 0.5000 5.22 >>> 0.5511 0.0000 0.5000 33.8 0.2500 99.53 >>> 0.9102 0.8730 0.0163 31.7 1.0000 9.29 * > But in <Substructure solution with SHELXD>, I found this sentence > ...A random selection of vectors from the Patterson peak > list (excluding Harker peaks), biased so that the high peaks > are chosen more often... > It seem that the Patterson peaks are selected randomly.So I am very > confused. > Can you give me a short introduction about the 'mult' indicates and the > rule of peaks selection? > Thank you very much! > Best wishes! > Ding wei > > -- Prof. George M. Sheldrick FRS Dept. Structural Chemistry, University of Goettingen, Tammannstr. 4, D37077 Goettingen, Germany Tel. +49-551-39-3021 or -3068 Fax. +49-551-39-22582
