Hi Maher,

The message is output from crunch2 and indicates it can not find peaks in its patterson function calculation. I would suggest to try using shelxc/d (you can do this within crank or other pipelines) and inputting a high resolution cut-off in substructure determination at 5.1 Angstrom and perhaps doing a few runs with different resolution cut offs in substructure determination. It appears your signal is weak, so I would also suggest to run crank2 instead (available in ccp4 6.4.0, if the updates are installed). Crank2 and crank do not differ in substructure determination (both call either shelxc/d or afro/crunch2), but if the correct substructure is found, and the anomalous signal is weak, crank2 is significantly better.

Feel free to email directly (off list) if you have any further questions about crank.

Best wishes,
Navraj

On Tue, Jul 1, 2014 at 4:42 AM, Maher Alayyoubi <[log in to unmask]> wrote:

Hi everyone,

I have two questions:

1- I was trying to run the program Acorn, on a SAD dataset (Se derivative) that was scaled in scalepack/HKL2000. converted to .mtz using scalepack2mtz, then edited in REVISE and Ecalc. But when I ran Acorn it gives me the error message "Segmentation fault".

Does anyone know what is going on?

2- The same dataset I ran on CRANK in an attempt to calculate a substructure and the program stopped with an error message: "not enough clear peaks in the patterson function" eventhough xtriage suggests I have a an anomalous signal until 5.1A. Does this mean the anomalous signal is so weak for CRANK to detect?

Thank you,

Maher