d1: DISTANCE ATOMS=1,10
vol: VOLUME 

METAD ARG=d1,vol SIGMA=0.1,0.2 HEIGHT=1.0 PACE=10 LABEL=md TEMP=300 GRID_MIN=0.0,120.0 GRID_MAX=2.0,130.0 BIASFACTOR=10 GRID_BIN=100,100 FMT=%14.6f

PRINT ...
  STRIDE=1
  ARG=d1,vol,md.bias 
  FILE=COLVAR FMT=%6.3f
... PRINT

FLUSH STRIDE=100

ENDPLUMED

