 Search for best fit using 30 tries with command "fit #1 #0 search 30"
 Fits appear all along filament, many are equivalent due to symmetry
of the filament.

 Determine map symmetry to eliminate equivalent fits.
 Command "measure symmetry #0 helix 20,180,opt minimumCorrelation 0.95".
 The "helix" option gives Chimera a hint about helical parameters.
 The "minimumCorrelation" option accounts for this unusual map where
the helix does not extend to the edges of the volume box.
 View symmetry copies of molecule with command "sym #1 group #0 surf true".
 Remove symmetry copies with "~sym #1" (note leading tilde character
which means "undo" in Chimera commands).

 Clear fit list.
 Rerun previous fitting command "fit #1 #0 search 50".
 Clear fit list.
 Use correlation optimization "fit #1 #0 search 50 res 19".
