CKRDEX    CKRDEX    CKRDEX    CKRDEX    CKRDEX    CKRDEX    CKRDEX    
          **********************************************
                    **************************
                              ******

SUBROUTINE CKRDEX (I, RCKWRK, RD)
Get/put the perturbation factor of the Ith reaction

INPUT
I         - Integer scalar, reaction index;
            I > 0 gets RD(I) from RCKWRK
            I < 0 puts RD(I) into RCKWRK
RCKWRK(*) - Real    workspace array; dimension at least LENRCK.

If I < 1:
RD        - Real scalar, perturbation factor for reaction I;
            cgs units, mole-cm-sec-K.

OUTPUT
If I > 1:
RD        - Real scalar, perturbation factor for reaction I;
            cgs units, mole-cm-sec-K.