diff --git a/doc/src/set.rst b/doc/src/set.rst
index c6c44ceb45..3d970d7044 100644
--- a/doc/src/set.rst
+++ b/doc/src/set.rst
@@ -16,9 +16,10 @@ Syntax
 * keyword = *type* or *type/fraction* or *type/ratio* or *type/subset*
   or *mol* or *x* or *y* or *z* or *vx* or *vy* or *vz* or *charge* or
   *dipole* or *dipole/random* or *quat* or *spin/atom* or *spin/atom/random* or
-  *quat* or *quat/random* or *diameter* or *shape* or
-  *length* or *tri* or *theta* or *theta/random* or *angmom* or
-  *omega* or *mass* or *density* or *density/disc* or
+  *spin/electron* or *radius/electron* or
+  *quat* or *quat/random* or *diameter* or *shape* or *length* or *tri* or
+  *theta* or *theta/random* or *angmom* or *omega* or
+  *mass* or *density* or *density/disc* or
   *volume* or *image* or *bond* or *angle* or *dihedral* or
   *improper* or *sph/e* or *sph/cv* or *sph/rho* or
   *smd/contact/radius* or *smd/mass/density* or *dpd/theta* or
@@ -62,6 +63,10 @@ Syntax
        *spin/atom/random* value = seed Dlen
          seed = random # seed (positive integer) for magnetic spin orientations
          Dlen = magnitude of magnetic spin vector (in Bohr magneton's unit)
+       *radius/electron* values = eradius
+         eradius = electron radius (or fixed-core radius) (distance units)
+       *spin/electron* value = espin
+         espin = electron spin (+1/-1), 0 = nuclei, 2 = fixed-core, 3 = pseudo-cores (i.e. ECP)
        *quat* values = a b c theta
          a,b,c = unit vector to rotate particle around via right-hand rule
          theta = rotation angle (degrees)
@@ -290,6 +295,16 @@ Keyword *spin/atom/random* randomizes the orientation of the magnetic spin
 vectors for the selected atoms and sets the magnitude of each to the
 specified *Dlen* value.  This keyword was previously called *spin/random*.
 
+.. versionadded:: TBD
+
+Keyword *radius/electron* uses the specified value to set the radius of
+electrons or fixed cores.
+
+.. versionadded:: TBD
+
+Keyword *spin/electron* sets the spin of an electron (+/- 1) or indicates
+nuclei (=0), fixed-cores (=2), or pseudo-cores (= 3).
+
 Keyword *quat* uses the specified values to create a quaternion
 (4-vector) that represents the orientation of the selected atoms.  The
 particles must define a quaternion for their orientation
diff --git a/src/set.cpp b/src/set.cpp
index 601bdd9e56..80c524f8a4 100644
--- a/src/set.cpp
+++ b/src/set.cpp
@@ -976,6 +976,8 @@ void Set::set(int keyword)
     // set magnetic moments
 
     else if (keyword == SPIN_ATOM) {
+      if (dvalue < 0.0)
+        error->one(FLERR,"Incorrect value for atomic spin magnitude: {}", dvalue);
       double **sp = atom->sp;
       double inorm = 1.0/sqrt(xvalue*xvalue+yvalue*yvalue+zvalue*zvalue);
       sp[i][0] = inorm*xvalue;
@@ -984,6 +986,23 @@ void Set::set(int keyword)
       sp[i][3] = dvalue;
     }
 
+    // set electron radius
+
+    else if (keyword == RADIUS_ELECTRON) {
+      atom->eradius[i] = dvalue;
+      if (dvalue < 0.0)
+        error->one(FLERR,"Incorrect value for electron radius: {}", dvalue);
+    }
+
+    // set electron spin
+
+    else if (keyword == SPIN_ELECTRON) {
+      if ((dvalue == -1) || (dvalue == 1) || (dvalue == 0) || (dvalue == 2) || (dvalue == 3))
+        atom->spin[i] = (int)dvalue;
+      else
+        error->one(FLERR,"Incorrect value for electron spin: {}", dvalue);
+    }
+
     // set quaternion orientation of ellipsoid or tri or body particle or sphere/bpm
     // enforce quat rotation vector in z dir for 2d systems