&             exp( (24.2-0.085*t)*(pressc-1.0)/(83.143*tk) )

     &             exp( (16.4-0.040*t)*(pressc-1.0)/(83.143*tk) )

     &          dlogtk + 0.053105*sqrts*tk)

           pfactor = - (dv/(bigR*tk))*pressc

     &               + (0.5*dk/(bigR*tk))*pressc*pressc

         tmpa1 = - 171.9065 - (0.077993*tk) + (2839.319/tk)

     &            + (71.595*log10(tk))

         tmpa2 = +(-0.77712 + (0.0028426*tk) + (178.34/tk) )*sqrts

        _RL  tk

           tk = 273.15 _d 0 + t

           tk100 = tk/100. _d 0

           invtk=1.0 _d 0/tk

           dlogtk=log(tk)

     &          dlogtk + 0.053105 _d 0*sqrts*tk)

        _RL  tk

           tk = 273.15 + t

           tk100 = tk/100.0

           invtk=1.0/tk

           dlogtk=log(tk)