diff --git a/doc/Section_intro.html b/doc/Section_intro.html
index 5f3295ef0d..1d3758621b 100644
--- a/doc/Section_intro.html
+++ b/doc/Section_intro.html
@@ -129,7 +129,7 @@ commands)
 <LI>  dihedral potentials: harmonic, CHARMM, multi-harmonic, helix,     class 2 (COMPASS), OPLS
 <LI>  improper potentials: harmonic, cvff, class 2 (COMPASS)
 <LI>  hybrid potentials: multiple pair, bond, angle, dihedral, improper     potentials can be used in one simlulation
-<LI>  overlayed potentials: multiple pair potentials can be superposed
+<LI>  overlayed potentials: superposition of multiple pair potentials
 <LI>  polymer potentials: all-atom, united-atom, bead-spring, breakable
 <LI>  water potentials: TIP3P, TIP4P, SPC
 <LI>  long-range Coulombics and dispersion: Ewald,     PPPM (similar to particle-mesh Ewald), Ewald/N for long-range Lennard-Jones
diff --git a/doc/Section_intro.txt b/doc/Section_intro.txt
index e411358bd7..0213b81768 100644
--- a/doc/Section_intro.txt
+++ b/doc/Section_intro.txt
@@ -130,7 +130,7 @@ commands)
   improper potentials: harmonic, cvff, class 2 (COMPASS)
   hybrid potentials: multiple pair, bond, angle, dihedral, improper \
     potentials can be used in one simlulation
-  overlayed potentials: multiple pair potentials can be superposed
+  overlayed potentials: superposition of multiple pair potentials
   polymer potentials: all-atom, united-atom, bead-spring, breakable
   water potentials: TIP3P, TIP4P, SPC
   long-range Coulombics and dispersion: Ewald, \