  We present a study of the three-dimensional structure of the molecular clouds
in the Galactic Centre (GC) using CO emission and OH absorption lines. Two CO
isotopologue lines, $^{12}$CO ($J$=1$\rightarrow$0) and $^{13}$CO
($J$=1$\rightarrow$0), and four OH ground-state transitions, surveyed by the
Southern Parkes Large-Area Survey in Hydroxyl (SPLASH), contribute to this
study. We develop a novel method to calculate the OH column density, excitation
temperature, and optical depth precisely using all four OH lines, and we employ
it to derive a three-dimensional model for the distribution of molecular clouds
in the GC for six slices in Galactic latitude. The angular resolution of the
data is 15.5 arcmin, which at the distance of the GC (8.34 kpc) is equivalent
to 38 pc. We find that the total mass of OH in the GC is in the range 2400-5100
Solar mass . The face-on view at a Galactic latitude of b = 0{\deg} displays a
bar-like structure with an inclination angle of 67.5 $\pm$ 2.1{\deg} with
respect to the line of sight. No ring-like structure in the GC is evident in
our data, likely due to the low spatial resolution of the CO and OH maps.
