diff --git a/org/qmckl_distance.org b/org/qmckl_distance.org
index 77b63f3..bccf454 100644
--- a/org/qmckl_distance.org
+++ b/org/qmckl_distance.org
@@ -817,7 +817,7 @@ assert(test_qmckl_dist(context) == QMCKL_SUCCESS);
    pairs of points in two sets, one point within each set:
 
    \[
-   R_{ij} = \left( 1 - \exp{-\kappa C_{ij}}\right)/\kappa
+   C_{ij} = \left( 1 - \exp{-\kappa C_{ij}}\right)/\kappa
    \]
 
    If the input array is normal (~'N'~), the xyz coordinates are in