double precision pi,pisq,pisqo6
      parameter(pi=3.1415926535897932385d0,pisq=pi*pi,pisqo6=pisq/6d0)

      double precision zip,half,one,two,three,four,eight
      parameter(zip=0d0,half=0.5d0,one=1d0,two=2d0)
      parameter(three=3d0,four=4d0,eight=8d0)

      double complex im,impi,czip,cone
      parameter(im=(0d0,1d0),impi=(0d0,3.1415926535897932385d0),
     . czip=(0d0,0d0),cone=(1d0,0d0))