Mapping the Galactic Disk with the LAMOST and Gaia Red Clump Sample VII:
  the Stellar Disk Structure Revealed by the Mono-abundance Populations
  Using a sample of 96,201 primary red clump (RC) stars selected from the
LAMOST and Gaia surveys, we investigate the stellar structure of the Galactic
disk. The sample stars show two separated sequences of high-[{\alpha}/Fe] and
low-[{\alpha}/Fe] in the [{\alpha}/Fe]-[Fe/H] plane. We divide the sample stars
into five mono-abundance populations (MAPs) with different ranges of
[{\alpha}/Fe] and [Fe/H], named as the high-[{\alpha}/Fe], high-[{\alpha}/Fe] &
high-[Fe/H], low-[Fe/H], solar, high-[Fe/H] MAPs respectively. We present the
stellar number density distributions in the R R Z plane, and the scale heights
and scale lengths of the individual MAPs by fitting their vertical and radial
density profiles. The vertical profiles, the variation trend of scale height
with the Galactocentric radius, indicate that there is a clear disk flare in
the outer disk both for the low-[{\alpha}/Fe] and the high-[{\alpha}/Fe] MAPs.
While the radial surface density profiles show a peak radius of 7 kpc and 8 kpc
for the high-[{\alpha}/Fe] and low-[{\alpha}/Fe] MAPs, respectively. We also
investigate the correlation between the mean rotation velocity and metallicity
of the individual MAPs, and find that the mean rotation velocities are well
separated and show different trends between the high-[{\alpha}/Fe] and the
low-[{\alpha}/Fe] MAPs. At last, we discuss the character of the
high-[{\alpha}/Fe] & high-[Fe/H] MAP and find that it is more similar to the
high-[{\alpha}/Fe] MAP either in the radial and vertical density profiles or in
the rotation velocity.
