1r1: RMSD REFERENCE=ref.pdb TYPE=OPTIMAL-FAST NOPBC 2r1x: RMSD REFERENCE=refx.pdb TYPE=OPTIMAL-FAST NOPBC 3r2: RMSD REFERENCE=ref2.pdb TYPE=OPTIMAL-FAST NOPBC 4#num-r2: RMSD REFERENCE=ref2.pdb TYPE=OPTIMAL-FAST NUMERICAL_DERIVATIVES 5 6DUMPDERIVATIVES FILE=deriv ARG=r1,r1x FMT=%12.8f 7#DUMPDERIVATIVES FILE=check ARG=r2,num-r2 FMT=%12.8f 8 9PRINT ... 10 STRIDE=1 11 ARG=* 12 FILE=COLVAR FMT=%12.8f 13... PRINT 14 15ENDPLUMED 16 17