[sassie-web/sassie2-feedback][suggestion] 'SasCal Running state' xin.gao.15@ucl.ac.uk

[genapp.not...@gmail.com]

subject : SasCal Running state
from : xingaoucl
email : xin.g...@ucl.ac.uk
level : suggestion
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Dear Joseph, I did the SasCalc run with 6GB a DCD file. The state said it was done, but I did not find any finished files. Is it still running or did I do something wrong with it?Many Thanks

[mads...@gmail.com]

Hi,

Looking at your inputs you are requesting 1149 q-points with a maximum q of 0.15 (1/A).  When I use your PDB/DCD pair and the same maximum q but with a more reasonable number of q-points (say 21 to 31) the program runs to completion correctly.  It could be that given the very large number of q-points that you have exceeded the capability of the program.  The memory allocation is a function of the number of atoms, number of q-points, number of golden vectors, and number of frames and therefore for larger systems using a large number of q-points could be limiting.

Note from the SASSIE-web SasCalc documentation (see the provided link for a description of the information content in a SAS profile):

• More data points may not be mathematically justified. For SAS there is limited information content related to the size of the molecule measured in the experimental scattering data. 15 to 31 points are generally used. See BIOISIS for a theoretical and pratical reasoning regarding the number of points one should use.

Cheers,

Joseph