plumed.dat

# set up two variables for Phi and Psi dihedral angles 
phi: TORSION ATOMS=5,7,9,15
psi: TORSION ATOMS=7,9,15,17	

# Define basis functions. 
BF_FOURIER ...
 ORDER=15
 INTERVAL_MIN=-pi
 INTERVAL_MAX=pi
 LABEL=bf1
... BF_FOURIER

BF_FOURIER ...
 ORDER=15
 INTERVAL_MIN=-pi
 INTERVAL_MAX=pi
 LABEL=bf2
... BF_FOURIER

# Target a uniform distribution
td_uniform: TD_UNIFORM

# Define expansion.
VES_LINEAR_EXPANSION ...
 ARG=phi,psi
 BASIS_FUNCTIONS=bf1,bf2
 LABEL=b1
 TEMP=298.15
 GRID_BINS=31,31
 TARGET_DISTRIBUTION=td_uniform
... VES_LINEAR_EXPANSION

# Optimization algorithm
OPT_AVERAGED_SGD ...
  BIAS=b1
  STRIDE=500
  LABEL=o1
  STEPSIZE=0.5
  FES_OUTPUT=10
  BIAS_OUTPUT=10
  COEFFS_OUTPUT=10
... OPT_AVERAGED_SGD

PRINT ARG=* STRIDE=1000 FILE=COLVAR