From f7ea42f90fd8c84b909ffe1b6d7dc4217e8b48e3 Mon Sep 17 00:00:00 2001
From: Luke Shingles <luke.shingles@gmail.com>
Date: Fri, 7 Mar 2025 21:31:35 +0000
Subject: [PATCH] Update grid.cc

---
 grid.cc | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/grid.cc b/grid.cc
index b2e18f901..da8df56bf 100644
--- a/grid.cc
+++ b/grid.cc
@@ -2543,13 +2543,14 @@ auto get_totmassradionuclide(const int z, const int a) -> double {
         d_coordminboundary[d] = -1;
       }
 
-      const double t_coordmaxboundary = ((pktposgridcoord[d] - (pktvelgridcoord[d] * tstart)) /
-                                         (cellcoordmax[d] - (pktvelgridcoord[d] * globals::tmin)) * globals::tmin) -
-                                        tstart;
-
-      d_coordmaxboundary[d] = CLIGHT_PROP * t_coordmaxboundary;
-      if ((pktvelgridcoord[d] - (pktposgridcoord[d] / tstart)) < 0) {
+      if (pktvelgridcoord[d] < (pktposgridcoord[d] / tstart)) {
         d_coordmaxboundary[d] = -1;
+      } else {
+        const double t_coordmaxboundary = ((pktposgridcoord[d] - (pktvelgridcoord[d] * tstart)) /
+                                           (cellcoordmax[d] - (pktvelgridcoord[d] * globals::tmin)) * globals::tmin) -
+                                          tstart;
+
+        d_coordmaxboundary[d] = CLIGHT_PROP * t_coordmaxboundary;
       }
     }
   } else {