Pspc::AmIteratorFilm

An AmIteratorFilm is an iterator that uses an Anderson Mixing (AM) algorithm to solve the SCFT equations for a thin film. For more information, see the detailed summary at Thin Films .

The parameter file format for an AmIteratorFilm object is:

AmIteratorFilm{
   epsilon             float
   maxItr*             int (200 by default)
   maxHist*            int (50 by default) 
   errorType*          string ("norm", "rms", "max", or "relNorm".
                       "relNorm" by default)
   isFlexible*         bool (0 or 1, 0 by default)   
   flexibleParams*     Array [ bool ] (nParameters elements, each element 0 or 1)
   scaleStress*        float (10.0 by default)
   normalVecId         int (0, 1, or 2)   
   interfaceThickness  float  
   wallThickness       float 
   chiBottom           Array [ float ] (nMonomer elements)
   chiTop              Array [ float ] (nMonomer elements)
}

Here, as elsewhere, labels followed by an asterisk (*) represent optional elements.

Parameters and subblocks are described below:

epsilon	Error tolerance. Iteration stops if the scalar error drops below this value.
maxItr*	Maximum number of iterations that will be attempted (200 by default)
maxHist*	The number of histories (previous state space points) to use to construct a new trial state during each iteration (50 by default)
errorType*	Error type to use to define the scalar error that is compared to epsilon to test for convergence. Allowed values of this string are "norm", "rms", "max" and "relNorm", with "relNorm" set by default. All error types are defined in terms of some sort of norm of the residual vector. Definitions are the same as for the AmIterator algorithm.
isFlexible*	Boolean (0 or 1, default 0) indicating whether the unit cell is flexible. If isFlexible is true (1), the iterator will optimize the flexible lattice parameters to minimize the free energy.
flexibleParams*	Use flexibleParams to declare only some lattice parameters as flexible. This entry is only allowed if isFlexible is set set to true. This array should contain one entry for each lattice parameter, and each entry should be either 1 (true, parameter is flexible) or 0 (false, parameter is fixed). For example, flexibleParams[ 0 1 0 1 ] will set the second and fourth lattice parameters as flexible, and fix the other two. If isFlexible is true but flexibleParams is not provided, then all lattice parameters will be flexible.
scaleStress*	If isFlexible = true, the components of the residual that correspond to stress components are multiplied by scaleStress (real, optional, 10.0 by default). Allows users to control the relative importance of the stress vs. residuals in the SCF equations.
normalVecId	Index (either 0, 1, or 2) of the Bravais lattice basis vector that is oriented normal to the walls confining the thin film.
interfaceThickness	Thickness of the wall/polymer interface. As interfaceThickness decrease, the volume fraction of the wall increases more rapidly from 0 to 1 with changes in normal coordinate. Recommendation is to use 0.5Rg or less, where Rg is the radius of gyration of the majority species in the SCFT system.
wallThickness	thickness of the wall (i.e., the region from which the mixture is excluded). Recommendation is to use at least twice the interfaceThickness value.
chiBottom	Array of values representing the relative strengths of chemical interactions between the bottom wall and each monomer species in the system, in the form of a Flory-Huggins-like chi value. Each entry of the array gives the chi value that defines the chemical interactions of one monomer species with the wall. This array has nMonomer entries. Large values represent unfavorable interactions. The "bottom wall" here is defined as the wall that contains the origin.
chiTop	Array of values representing the relative strengths of chemical interactions between the top wall and each monomer species in the system, in the form of a Flory-Huggins-like chi value. Each entry of the array gives the chi value that defines the chemical interactions of one monomer species with the wall. This array has nMonomer entries. Large values represent unfavorable interactions. The "top wall" here is defined as the wall that does not contain the origin.