code: public static Atom scaleEquals(Atom a, double s) {
  		double x = a.getX();
  		double y = a.getY();
  		double z = a.getZ();
  
  		x *= s;
  		y *= s;
  		z *= s;
  
  		//Atom b = new AtomImpl();
  		a.setX(x);
  		a.setY(y);
  		a.setZ(z);
  
  		return a;
  	}
docs: Multiply elements of a by s (in place)
  
  @param a
  @param s
  @return the modified a