  AIMS. We derive the morphology of the stellar component in the outer halo
volume, and search for possible overdensities due to substructures therein.
  METHODS. We made use of some of the data releases of the spectroscopic survey
LAMOST DR8-DR9 in tandem with distance determinations for two subsamples, that
is, of K-giants and M-giants, respectively, making up 60,000 stars. These
distance are obtained through Bayesian techniques that derive absolute
magnitudes as a function of measured spectroscopic parameters. Our calculation
of the density from these catalogues requires: (1) derivation of the selection
function; and (2) a correction for the convolution of the distance errors,
which we carried out with Lucy's inversion of the corresponding integral
equation.
  RESULTS. The stellar density distribution of the outer halo (distance to the
Galactic centre, $r_G$, of between 25 and 90 kpc) is a smooth monotonously
decreasing function with a dependence of approximately $\rho \propto r_G^{-n}$,
with $n=4.6\pm 0.4$ for K-giants and $n=4.5\pm 0.2$ for M-giants, and with a
insignificant oblateness. The value of $n$ is independent of the angular
distance to the Sagittarius tidal stream plane, which is what would be expected
if such a stream did not exist in the anticenter positions or had a negligible
imprint in the density distribution in the outer halo. Apart from random
fluctuations or minor anomalies in some lines of sight, we do not see
substructures superimposed in the outer halo volume within the resolution that
we are using and limited by the error bars. This constrains the mass of over-
and under-densities in the outer halo to be of $\lesssim 10^3$ M$_\odot
$/deg$^2$, whereas the total mass of the stellar halo, including inner and
outer parts, is $\sim 7\times 10^8$ M$_\odot $.
