MCADIF    MCADIF    MCADIF    MCADIF    MCADIF    MCADIF    MCADIF    
          **********************************************
                    **************************
                              ******

SUBROUTINE MCADIF (P, T, X, RMCWRK, D)
Returns mixture-averaged diffusion coefficients given pressure,
temperature, and species mole fractions.

INPUT
P         - Real scalar, pressure.
               cgs units, dynes/cm**2
T         - Real scalar, temperature.
               cgs units, K
X(*)      - Real array, mole fractions of the mixture;
            dimension at least KK, the total species count.
RMCWRK(*) - Real workspace array; dimension at least LENRMC.

OUTPUT
D(*)      - Real array, mixture diffusion coefficients;
            dimension at least KK, the total species count.
               cgs units, cm**2/s