From d78a9b188594a262bb84cb758fd8f13f75887966 Mon Sep 17 00:00:00 2001
From: Patrick Shriwise <pshriwise@gmail.com>
Date: Mon, 1 Aug 2022 17:34:39 -0500
Subject: [PATCH] Adding new interpolation entry.

---
 include/openmc/constants.h | 3 ++-
 openmc/data/function.py    | 2 +-
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/include/openmc/constants.h b/include/openmc/constants.h
index a7362ea9e..9c9a5f9b3 100644
--- a/include/openmc/constants.h
+++ b/include/openmc/constants.h
@@ -318,7 +318,8 @@ enum class Interpolation {
   lin_lin = 2,
   lin_log = 3,
   log_lin = 4,
-  log_log = 5
+  log_log = 5,
+  cubic = 6
 };
 
 enum class RunMode {
diff --git a/openmc/data/function.py b/openmc/data/function.py
index b0390d19c..f03319eed 100644
--- a/openmc/data/function.py
+++ b/openmc/data/function.py
@@ -13,7 +13,7 @@ from openmc.mixin import EqualityMixin
 from .data import EV_PER_MEV
 
 INTERPOLATION_SCHEME = {1: 'histogram', 2: 'linear-linear', 3: 'linear-log',
-                        4: 'log-linear', 5: 'log-log'}
+                        4: 'log-linear', 5: 'log-log', 6 : 'cubic'}
 
 
 def sum_functions(funcs):