From dc2e386a29657b887dacfdeb7c545cee74e34805 Mon Sep 17 00:00:00 2001
From: Olaf Schumann <o.j.schumann@gmail.com>
Date: Mon, 17 Jan 2022 08:49:46 +0100
Subject: [PATCH] Update src/secondary_thermal.cpp

Co-authored-by: Paul Romano <paul.k.romano@gmail.com>
---
 src/secondary_thermal.cpp                     | 8 +++-----
 tests/regression_tests/triso/results_true.dat | 2 +-
 2 files changed, 4 insertions(+), 6 deletions(-)

diff --git a/src/secondary_thermal.cpp b/src/secondary_thermal.cpp
index 6e04092b35..3677f6ed3a 100644
--- a/src/secondary_thermal.cpp
+++ b/src/secondary_thermal.cpp
@@ -4,6 +4,8 @@
 #include "openmc/random_lcg.h"
 #include "openmc/search.h"
 
+#include <gsl/gsl-lite.hpp>
+
 #include "xtensor/xview.hpp"
 
 #include <cmath> // for log, exp
@@ -38,11 +40,7 @@ void CoherentElasticAE::sample(
 
   const auto& energies {xs_.bragg_edges()};
 
-  if (E_in < energies.front()) {
-    // XS is zero for E < energies[0] -> no scatter
-    mu = 1.0;
-    return;
-  }
+  Expects(E_in >= energies.front());
 
   const int i = lower_bound_index(energies.begin(), energies.end(), E_in);
 
diff --git a/tests/regression_tests/triso/results_true.dat b/tests/regression_tests/triso/results_true.dat
index 31d4a8544f..279094ab3d 100644
--- a/tests/regression_tests/triso/results_true.dat
+++ b/tests/regression_tests/triso/results_true.dat
@@ -1,2 +1,2 @@
 k-combined:
-1.406055E+00 9.581397E-02
+1.406055E+00 9.581396E-02