Symmetrize S matrix in CPCMSolver

Author: Roberto Di Remigio

CHANGELOG.md

@@ -2,6 +2,11 @@
 
 ## [Unreleased]
 
+### Changed
+
+- The `CPCMSolver` object now stores the scaled, Hermitian, symmetry-adapted S matrix.
+  Polarization weights are then directly computed from the incoming MEP.
+
 ## [v1.1.3] (2016-07-03)
 
 ### Changed

src/solver/CPCMSolver.cpp

@@ -47,6 +47,8 @@ void CPCMSolver::buildSystemMatrix_impl(const Cavity & cavity, const IGreensFunc
   double epsilon = profiles::epsilon(gf_o.permittivity());
   S_ = gf_i.singleLayer(cavity.elements());
   S_ /= (epsilon - 1.0)/(epsilon + correction_);
+  // Get in Hermitian form
+  if (hermitivitize_) hermitivitize(S_);
   TIMER_OFF("Computing S");
 
   // Symmetry-pack
@@ -78,8 +80,6 @@ Eigen::VectorXd CPCMSolver::computeCharge_impl(const Eigen::VectorXd & potential
   int irrDim = fullDim/nrBlocks;
   charge.segment(irrep*irrDim, irrDim) =
     - blockS_[irrep].ldlt().solve(potential.segment(irrep*irrDim, irrDim));
-  // Symmetrize ASC charge := (charge + charge*)/2
-  if (hermitivitize_) hermitivitize(charge);
 
   return charge;
 }

src/solver/CPCMSolver.hpp

@@ -45,9 +45,9 @@ class IGreensFunction;
  *  \author Roberto Di Remigio
  *  \date 2013, 2016
  *
- *  \note We store the unsymmetrized S matrix and use a robust
- *  Cholesky decomposition to solve for the ASC. The ASC is then
- *  symmetrized. This avoids computing and storing the inverse explicitly.
+ *  \note We store the scaled, Hermitian, symmetrized S matrix and use a robust
+ *  Cholesky decomposition to solve for the ASC.
+ *  This avoids computing and storing the inverse explicitly.
  *  The S matrix is already scaled by the dielectric factor entering the
  *  definition of the conductor model!
  */