optimize overall <xray-optimize-overall-statement> end

<xray-optimize-overall-statement> :==

  name=<reciprocal-space-object>
  --{Structure factor whose overall B-factor is optimized. Default=fcalc}
  drop=<real>
  --{Expected initial drop in energy (only for POWELL method). Default=40}
  nstep=<integer>
  --{Number of optimization steps. Default=20}
  tolerance=<real>
  --{Minimum gradient that forces exit of optimization. Default=0.0001}
  maxfevaluations=<integer>
  --{For LBFGS method only: Maximum number of energy evalulations during 
     line search. Default=10}
  method=powell|lbfgs
  --{Minimization method: POWELL or LBFGS. Default=POWELL}
  anisotropic=<logical>
  --{If true then the anisotropic components are refined. Default=false}
  isotropic=<logical>
  --{If true then the isotropic thermal factor is refined.
     If false, the trace is restricted to zero. Default=true}
  kscale=<logical>
  --{Refine overall scale. Default=false}
  bscale=<logical>
  --{Refine overall B-tensor. Default=true}
  k=<real>
  --{Initial overall scale. Default=1.0}
  b=<real>
  --{Starting isotropic B-factor shift. Default=0}
  b11=<real> b22=<real> b33=<real> b12=<real> b13=<real> b23=<real>
  --{Starting anisotropic B-factor shifts. Default=0}
  restriction=all|offd|none
  --{Restrictions due to symmetry:
     - all: all parameters (this is the default).
     - offd: off-diagonal elements only.
     - none: no restrictions.}

  --{The following must be defined:
     - the reciprocal space object <reciprocal-space-object>.
     - target and dtarget(<reciprocal-space-object>).
     The following symbols will be declared:
     - for isotropic B-factor refinement:
       $kscale * exp(-$bscale s^2 )/4.0 * <reciprocal-space-object>
     - for anisotropic B-factor refinement:
       $kscale * exp(-( $b2_11*h*h*$astar*$astar
                       +$b2_22*k*k*$bstar*$bstar
                       +$b2_33*l*l*$cstar*$cstar
                   +2.0*$b2_12*h*k*$astar*$bstar
                   +2.0*$b2_13*h*l*$astar*$cstar
                   +2.0*$b2_23*k*l*$bstar*$cstar)/4.0)
               * <reciprocal-space-object>}