Check that the relative permittivity epsilon is always strictly positive (#2906)

1 files changed, 6 insertions, 0 deletions

diff --git a/Source/FieldSolver/FiniteDifferenceSolver/MacroscopicProperties/MacroscopicProperties.cpp b/Source/FieldSolver/FiniteDifferenceSolver/MacroscopicProperties/MacroscopicProperties.cpp
index 2a35102cf..8f0e7d553 100644
--- a/Source/FieldSolver/FiniteDifferenceSolver/MacroscopicProperties/MacroscopicProperties.cpp
+++ b/Source/FieldSolver/FiniteDifferenceSolver/MacroscopicProperties/MacroscopicProperties.cpp
@@ -150,6 +150,12 @@ MacroscopicProperties::InitData ()
         InitializeMacroMultiFabUsingParser(m_eps_mf.get(), m_epsilon_parser->compile<3>(), lev);
 
     }
+    // In the Maxwell solver, `epsilon` is used in the denominator.
+    // Therefore, it needs to be strictly positive
+    bool const local=true;
+    AMREX_ALWAYS_ASSERT_WITH_MESSAGE( m_eps_mf->min(0,0,local) > 0,
+    "WarpX encountered zero or negative values for the relative permittivity `epsilon`. Please check the initialization of `epsilon`.");
+
     // Initialize mu
     if (m_mu_s == "constant") {