Merge pull request #198 from mir-group/minorFixes

Minor bugfix: OMP used on for loops over iterators

src/bands/active_bandstructure.cpp

@@ -546,8 +546,12 @@ void ActiveBandStructure::buildOnTheFly(Window &window, Points points_,
   std::vector<int> filteredThreadPoints;
   std::vector<std::vector<int>> filteredThreadBands;
 
+  std::vector<size_t> pointsIter = mpi->divideWorkIter(points_.getNumPoints()); 
   #pragma omp for nowait schedule(static)
-  for (int ik : mpi->divideWorkIter(points_.getNumPoints())) {
+  for (size_t iik = 0; iik < pointsIter.size(); iik++) { 
+
+    int ik = pointsIter[iik];
+
     Point point = points_.getPoint(ik);
     // diagonalize harmonic hamiltonian
     auto tup = h0.diagonalize(point);
@@ -820,7 +824,9 @@ StatisticsSweep ActiveBandStructure::buildAsPostprocessing(
   std::vector<std::vector<int>> filteredThreadBands;
 
   #pragma omp for nowait schedule(static)
-  for (int ik : parallelIter) {
+  for (int iik = 0; iik < parallelIter.size(); iik++) {
+
+    int ik = parallelIter[iik];
 
     auto ikIdx = WavevectorIndex(ik);
     //    Eigen::VectorXd theseEnergies =

src/bte/phel_scattering.cpp

@@ -79,8 +79,13 @@ void PhElScatteringMatrix::builder(VectorBTE *linewidth,
   // precompute Fermi-Dirac populations
   Eigen::Tensor<double,3> fermiTerm(numCalculations, numKPoints, nb1Max);
   fermiTerm.setZero();
+
+  std::vector<size_t> kIterator = mpi->divideWorkIter(numKPoints);
   #pragma omp parallel for
-  for (int ik : mpi->divideWorkIter(numKPoints)) {
+  for (int iik = 0; iik < kIterator.size(); iik++) {
+
+    int ik = kIterator[iik]; // avoid omp parallel on iterator loops 
+
     WavevectorIndex ikIdx(ik);
     Eigen::VectorXd energies = getElBandStructure().getEnergies(ikIdx);
     int nb1 = energies.size();
@@ -109,8 +114,13 @@ void PhElScatteringMatrix::builder(VectorBTE *linewidth,
   int nb3Max = 3 * getPhBandStructure().getPoints().getCrystal().getNumAtoms();
   Eigen::MatrixXcd polarData(numQPoints, nb3Max);
   polarData.setZero();
+
+  std::vector<size_t> qIterator = mpi->divideWorkIter(numQPoints); 
+
   #pragma omp parallel for
-  for (int iq : mpi->divideWorkIter(numQPoints)){
+  for (int iiq = 0; iiq < int(qIterator.size()); iiq++) { 
+
+    int iq = qIterator[iiq]; // avoid issues with omp on iterator loops
     WavevectorIndex iqIdx(iq);
     auto q3C = getPhBandStructure().getWavevector(iqIdx);
     auto ev3 = getPhBandStructure().getEigenvectors(iqIdx);