Hi - Just a little thing but I sometimes get segmentation faults with do_dssp. I found I can stop it by replacing for(i=naccr-10;i<naccr; i++) snew(accr[i],atoms->nres); with for(i=naccr-10; i<naccr; i++) snew(accr[i],atoms->nres+10); at line 483-4 of src/tools/do_dssp.c (there are similar +10s in some other snews just before). Graham