From 9edc7c1ffd42d84fbe445053a881c76d133cef6f Mon Sep 17 00:00:00 2001
From: "Eric T. Johnson" <yut23@users.noreply.github.com>
Date: Fri, 21 Jul 2023 15:29:55 -0400
Subject: [PATCH] Renumber the screening methods so null is at index 0 (#1286)

---
 Make.Microphysics_extern         |  8 ++++----
 nse_solver/nse_solver.H          |  4 ++--
 screening/screen.H               | 20 ++++++++++----------
 sphinx_docs/source/screening.rst |  8 ++++----
 4 files changed, 20 insertions(+), 20 deletions(-)

diff --git a/Make.Microphysics_extern b/Make.Microphysics_extern
index 2ee4665125..984e461e4c 100644
--- a/Make.Microphysics_extern
+++ b/Make.Microphysics_extern
@@ -15,13 +15,13 @@ ifeq ($(USE_NONAKA_PLOT),TRUE)
 endif
 
 SCREEN_METHOD ?= screen5
-ifeq ($(SCREEN_METHOD), screen5)
+ifeq ($(SCREEN_METHOD), null)
   DEFINES += -DSCREEN_METHOD=0
-else ifeq ($(SCREEN_METHOD), chugunov2007)
+else ifeq ($(SCREEN_METHOD), screen5)
   DEFINES += -DSCREEN_METHOD=1
-else ifeq ($(SCREEN_METHOD), chugunov2009)
+else ifeq ($(SCREEN_METHOD), chugunov2007)
   DEFINES += -DSCREEN_METHOD=2
-else ifeq ($(SCREEN_METHOD), null)
+else ifeq ($(SCREEN_METHOD), chugunov2009)
   DEFINES += -DSCREEN_METHOD=3
 else ifeq ($(SCREEN_METHOD), chabrier1998)
   DEFINES += -DSCREEN_METHOD=4
diff --git a/nse_solver/nse_solver.H b/nse_solver/nse_solver.H
index d5117ab67f..b8fadacbaf 100644
--- a/nse_solver/nse_solver.H
+++ b/nse_solver/nse_solver.H
@@ -89,7 +89,7 @@ void apply_nse_exponent(T& nse_state) {
   // if we use a non-null screening method.
   // Get the required terms to calculate coulomb correction term, u_c
 
-#if SCREEN_METHOD != 3
+#if SCREEN_METHOD != 0
 
   // three unit-less constants for calculating coulomb correction term
   // see Calder 2007, doi:10.1086/510709 for more detail
@@ -119,7 +119,7 @@ void apply_nse_exponent(T& nse_state) {
       // term for calculating u_c
 
       // if use non-null screening, calculate the coulomb correction term
-#if SCREEN_METHOD != 3
+#if SCREEN_METHOD != 0
       gamma = std::pow(zion[n], 5.0_rt/3.0_rt) * Gamma_e;
 
       // chemical potential for coulomb correction
diff --git a/screening/screen.H b/screening/screen.H
index 34599b27a8..868fa1060e 100644
--- a/screening/screen.H
+++ b/screening/screen.H
@@ -17,13 +17,13 @@ using namespace amrex;
 using namespace integrator_rp;
 
 #if SCREEN_METHOD == 0
-const std::string screen_name = "screen5";
+const std::string screen_name = "null";
 #elif SCREEN_METHOD == 1
-const std::string screen_name = "chugunov2007";
+const std::string screen_name = "screen5";
 #elif SCREEN_METHOD == 2
-const std::string screen_name = "chugunov2009";
+const std::string screen_name = "chugunov2007";
 #elif SCREEN_METHOD == 3
-const std::string screen_name = "null";
+const std::string screen_name = "chugunov2009";
 #elif SCREEN_METHOD == 4
 const std::string screen_name = "chabrier1998";
 #endif
@@ -977,16 +977,16 @@ void actual_screen(const plasma_state_t& state,
                    Real& scor, Real& scordt)
 {
 #if SCREEN_METHOD == 0
-    actual_screen5<do_T_derivatives>(state, scn_fac, scor, scordt);
-#elif SCREEN_METHOD == 1
-    chugunov2007<do_T_derivatives>(state, scn_fac, scor, scordt);
-#elif SCREEN_METHOD == 2
-    chugunov2009<do_T_derivatives>(state, scn_fac, scor, scordt);
-#elif SCREEN_METHOD == 3
     // null screening
     amrex::ignore_unused(state, scn_fac);
     scor = 1.0_rt;
     scordt = 0.0_rt;
+#elif SCREEN_METHOD == 1
+    actual_screen5<do_T_derivatives>(state, scn_fac, scor, scordt);
+#elif SCREEN_METHOD == 2
+    chugunov2007<do_T_derivatives>(state, scn_fac, scor, scordt);
+#elif SCREEN_METHOD == 3
+    chugunov2009<do_T_derivatives>(state, scn_fac, scor, scordt);
 #elif SCREEN_METHOD == 4
     chabrier1998<do_T_derivatives>(state, scn_fac, scor, scordt);
 #endif
diff --git a/sphinx_docs/source/screening.rst b/sphinx_docs/source/screening.rst
index fb5e837f1b..e54cd1a878 100644
--- a/sphinx_docs/source/screening.rst
+++ b/sphinx_docs/source/screening.rst
@@ -40,11 +40,11 @@ The options are:
   This includes the portion in the appendix that blends in the weak
   screening limit.
 
+* ``chabrier1998``:
+
+  This implements the screening of :cite:`Chabrier_1998` as well as the quantum corrections for strong screening according to screen5. This is suggested in the appendix of :cite:`Calder_2007`. This screening is compatible with NSE calculations unlike ``screen5``, ``chugunov2007``, and ``chugunov2009``. This screening should be valid in the weak screening regime, :math:`\Gamma < 0.1`, and strong screening regime, :math:`1 \lesssim \Gamma \lesssim 160`.
+
 * ``null`` :
 
   This disables screening by always returning 1 for the screening
   enhancement factor.
-
-* ``chabrier1998``:
-
-  This implements the screening of :cite:`Chabrier_1998` as well as the quantum corrections for strong screening according to screen5. This is suggested in the appendix of :cite:`Calder_2007`. This screening is compatible with NSE calculations unlike ``screen5``, ``chugunov2007``, and ``chugunov2009``. This screening should be valid in the weak screening regime, :math:`\Gamma < 0.1`, and strong screening regime, :math:`1 \lesssim \Gamma \lesssim 160`.