code: def _nemo_accpars(self,vo,ro):
          
          GM= self._amp*vo**2.*ro/2.
          return "0,1,%s,%s,0" % (GM,self.a*ro)
docs: NAME:
  
             _nemo_accpars
  
          PURPOSE:
  
             return the accpars potential parameters for use of this potential with NEMO
  
          INPUT:
  
             vo - velocity unit in km/s
  
             ro - length unit in kpc
  
          OUTPUT:
  
             accpars string
  
          HISTORY:
  
             2018-09-14 - Written - Bovy (UofT)