code: def move_to(self, r):
          '''Translate the molecule to a new position *r*.
          '''
          dx = r - self.r_array[0]
          self.r_array += df move_to(self, r):
          '''Translate the molecule to a new position *r*.
          '''
          dx = r - self.r_array[0]
          self.r_array += dx
docs: Translate the molecule to a new position *r*.