Just a few observations: I ran echo MODE SFCALC XYZIN\\n SYMM P21\\n RESO 30 3 | sfall xyzin a.pdb hklout temp.mtz > a.log and echo MODE SFCALC XYZIN\\n SYMM P21\\n RESO 30 3 | sfall xyzin b.pdb hklout temp.mtz > b.log and looked at a.log and b.log
They differ only as follows: a.log has First 10 atoms of atsort - orthog coordinates 16204FE1 ICS 6496 10.0180 -7.5680 56.1090 1.00 5.97 6 fractional coordinates 0.38411-0.05791 0.55929 First 10 atoms of atsort - orthog coordinates 16289FE1 ICS 7496 35.7530 7.5810-12.1820 1.00 5.91 6 fractional coordinates 0.38376 0.05800-0.12143 First 10 atoms of sorted file in asym unit - 20.61588 0.44071 0.44209 105.97 1.00 6 ***ZZZ END 10.38376 0.87857 0.05800 205.91 1.00 6 ***ZZZ END First atom of sorted file in atsort 20.61588 0.44071 0.44209 105.97 131.00 ***ZZZ END whereas b.log has First 10 atoms of atsort - orthog coordinates 16204FE1 ICS 6496 35.7530 7.5810-12.1820 1.00 5.91 6 fractional coordinates 0.38376 0.05800-0.12143 First 10 atoms of atsort - orthog coordinates 16289FE1 ICS 7496 10.0180 -7.5680 56.1090 1.00 5.97 6 fractional coordinates 0.38411-0.05791 0.55929 First 10 atoms of sorted file in asym unit - 10.38376 0.87857 0.05800 105.91 1.00 6 ***ZZZ END 20.61588 0.44071 0.44209 205.97 1.00 6 ***ZZZ END First atom of sorted file in atsort 10.38376 0.87857 0.05800 105.91 131.00 ***ZZZ END What I don't understand is why the sorted lists are different? Sorting should make the resulting lists look the same, to my limited understanding. What is peculiar about the coordinates of these atoms is that there x coordinate in fractional units is almost the same, and their y coordinate is mirrored at the origin.Maybe that could play a role. Kay