diff --git a/lib/atc/LammpsInterface.cpp b/lib/atc/LammpsInterface.cpp
index 78859aec6f..d584d159ea 100644
--- a/lib/atc/LammpsInterface.cpp
+++ b/lib/atc/LammpsInterface.cpp
@@ -235,6 +235,7 @@ std::string LammpsInterface::read_file(std::string filename) const
     eof = lammps_->comm->read_lines_from_file(fp,1,MAXLINE,buffer);
     s << buffer;
   }
+  fclose(fp);
   delete [] buffer;
   return s.str(); // can't copy the stream itself
 }
diff --git a/lib/atc/ParDiagonalMatrix.cpp b/lib/atc/ParDiagonalMatrix.cpp
index 15690b32ed..5888bedc04 100644
--- a/lib/atc/ParDiagonalMatrix.cpp
+++ b/lib/atc/ParDiagonalMatrix.cpp
@@ -88,6 +88,10 @@ namespace ATC_matrix {
     // Collect results on all processors
     allgatherv(_comm, C.ptr() + myMajorOffset * nMinor, myNMajor * nMinor,
                C.ptr(), majorCounts, majorOffsets);
+
+    delete[] majorCounts;
+    delete[] majorOffsets;
   }
 
+
 } // end namespace
diff --git a/lib/atc/Utility.h b/lib/atc/Utility.h
index f3bbd7d1fb..f9e99ff194 100644
--- a/lib/atc/Utility.h
+++ b/lib/atc/Utility.h
@@ -204,7 +204,9 @@ namespace ATC_Utility
   {
     double v;
     std::istringstream in(s);
-    return (in >> v);
+    in >> v;
+    // in.good() == true indicates, that not the whole string was converted.
+    return !(in.fail() || in.good());
   }
 
   /** convert a string to anything that has iostream::>> defined, second arg is to disambibuate type */