multiscale {<xray-multiscale-statement>} end

<xray-multiscale-statement> :==

  ffk=<real>
  --{Adjust overall scale. Default=0}
  selection=<xray-selection>
  --{Which structure factors to use in scaling. Default=(all)}
  set1=<reciprocal-space-object>
  --{Reference set for scaling. Default=fobs}
  k1=<real>
  --{Scale factor for the reference set. Default=-1}
  b1=<real>
  --{B-factor for the reference set. Default=0}
  set2=<reciprocal-space-object>
  --{Set to be scaled. Default=fcalc}
  k2=<real>
  --{Scale factor for this set. Default=none}
  b2=<real>
  --{B-factor for this set. Default=none}
  set<3..20>=<reciprocal-space-object>
  --{Set to be scaled. Default=none}
  k<3..20>=<real>
  --{Scale factor for this set. Default=none}
  b<3..20>=<real>
  --{B-factor for this set. Default=none}
  mode=target|tlow
  --{default=target}

  --{Least-squares optimize parameters for the target}
  --{================================================}
  update=<logical>
  --{Update parameters and multiply by overall scale factor. Default=true}
  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 then the trace is restricted to zero. Default=true}
  restriction=all|offd|none
  --{Restrictions due to symmetry for anisotropic B-factor refinement:
     - all: all parameters (default)
     - offd: off-diagonal only
     - none: no restrictions}

  --{The target to be minimized is:
       Target = sum(hkl) ( k1 exp(-b1 s^2/4) operand(set1) +
                           k2 exp(-b2 s^2/4) operand(set2) +
                                         ...
                           k20 exp(-b20 s^2/4) operand(set20) )

     The sum is performed over selected reflections.
     Optimization is performed by the method of least-squares.
     If ki or bi are positive they are treated as fixed.
     The results of optimization are returned in symbols:
       $k1, $k2, $k3 .... $k20
       $b1, $b2, $b3 .... $b20 for isotropic B-factors
       $b2_11, $b2_12 ... $b_33 for anisotropic B-factors}

  --{Least squares minimization options:}
  --{===================================}
  ncyc=<integer>
  --{Number of least-squares minimization cycles. Default=30}
  diag=<integer>
  --{Diagonal approximation for least-squares matrix. Default=0}
  eps=<real>
  --{Epsilon for convergence test. Default: 0.001}
  ksmin=<real>
  --{The minimum kscale restraint allowed. Default=0.0}
  bmin=<real>
  --{The minimum bscale restraint allowed. Default=-500.0}
  bmax=<real>
  --{The maximum bscale restraint allowed. Default=500.0}
  uniform=k|b
  --{Uniform=k: refine one uniform scale factor.
     Uniform=b: refine one uniform B-factor.
     Default=none}
  kinitial=<real>
  --{The initial scale factor for all non-fixed scale factors. Default=1.0}
  binitial=<real>
  --{The initial B-factor for all non-fixed B-factors. Default=0.0}

  --{Options for overall scale factors}
  --{=================================}
  resk=<real>
  --{The resolution boundary for two overall scale factors. Default=0.0A}
  ffk1=<real>
  --{Fixed overall scale factor for low resolution range. Default=0.0A}
  ffk2=<real>
  --{Fixed overall scale factor for high resolution range. Default=0.0A}