Comments

src/motions/coordinates.h

@@ -2,7 +2,10 @@
 #ifndef COORDINATES_H
 #define COORDINATES_H
 
+/// Coordinate types and rotations for molecular orientations on the unit sphere.
 namespace coordinates {
+
+/// Spherical position stored as (cos_theta, phi) to avoid repeated cos/acos.
 struct SphericalPos {
   double cos_theta;
   double phi;
@@ -14,7 +17,10 @@ struct CartesianPos {
   double z;
 };
 
-SphericalPos rotate(const SphericalPos &, double, double);
+/// Rotate a spherical position by polar angle alpha around an axis defined
+/// by azimuthal angle beta (rotation about the original position's z-axis).
+SphericalPos rotate(const SphericalPos &, double alpha, double beta);
+
 CartesianPos spherical_to_xyz(const SphericalPos &);
 SphericalPos xyz_to_spherical(const CartesianPos &);
 } // namespace coordinates