I have strange Fo-Fc map, where are several parallel + and - density
lines. The resolution of our data is about 2.1 and we have solved
structure to about 2.1. R is about 19 % and Rfree 24 %. Everything looks
good exept our Fo-Fc map.
I have calculated Fo-Fc map several times sometimes excluding the
highest or the lowest resolution reflections. I have also tried
calculations by excluding reflections which have the biggest differences
between fobs and fcalc, but everytime my Fo-Fc map looks almost exactly
to same. So have anybody any idea what could be wrong?