Maximum order of harmonics in SASREF

Interactive modelling (MASSHA, SASpy) and global minimization programs (SASREF, BUNCH, CORAL, GLOBSYMM)
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sch
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Maximum order of harmonics in SASREF

#1 Post by sch » 2014.02.24 23:15

Does SASREF force a limit on the maximum order of harmonics used from the alm for each component? I understand the more harmonics used the more computationaly expensive the calculation because of the cross term calculations but do I even have this option?

Whenever I input an alm file calculated using 15 or more spherical harmonic terms SASREF outputs:
SASREF --W- Lm reduced to compute cross term

I am surprised this is the case for lm=15 since this is the recommended value:
"The reference partial scattering amplitudes of the subunits have to be precomputed by the program CRYSOL (recommended values are lm=15, ns=51)."

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AL
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Re: Maximum order of harmonics in SASREF

#2 Post by AL » 2014.06.11 12:11

sch wrote:Does SASREF force a limit on the maximum order of harmonics used from the alm for each component? I understand the more harmonics used the more computationaly expensive the calculation because of the cross term calculations but do I even have this option?
Thanks for the feedback. SASREF from ATSAS 2.5.2 and earlier should definitely work with up to 14 harmonics (not sure about 15). It is planned to change the maximum order of harmonics to 20 in the next release and increase it up to 50 in the future. Of course the more harmonics - the longer it will take to fit.

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