  We use a three-dimensional magnetohydrodynamic simulation of the solar wind
to calculate cosmic ray diffusion coefficients throughout the inner heliosphere
($2~R_\odot - 3$ AU). The simulation resolves large-scale solar wind flow,
which is coupled to small-scale fluctuations through a turbulence model.
Simulation results specify background solar wind fields and turbulence
parameters, which are used to compute diffusion coefficients and study their
behavior in the inner heliosphere. The parallel mean free path is evaluated
using quasi-linear theory, while the perpendicular mean free path is determined
by non-linear guiding center theory with the random ballistic interpretation.
Several runs examine varying turbulent energy and different solar source dipole
tilts. We find that for most of the inner heliosphere, the radial mean free
path (mfp) is dominated by diffusion parallel to the mean magnetic field; the
parallel mfp remains at least an order of magnitude larger than the
perpendicular mfp, except in the heliospheric current sheet, where the
perpendicular mfp may be a few times larger than the parallel mfp; in the
ecliptic region, the perpendicular mfp may influence the radial mfp at
heliocentric distances larger than 1.5 AU; our estimations of the parallel mfp
in the ecliptic region at 1 AU agree well with the Palmer "consensus" range of
$0.08 - 0.3$ AU; solar activity increases perpendicular diffusion and reduces
parallel diffusion; the parallel mfp varies with rigidity $(P)$ as $P^{.33}$,
and the perpendicular mfp is weakly dependent on $P$; the mfps are weakly
influenced by the choice of long wavelength power spectra.
