  In this communication, we present the results of the triple differential
cross-section (TDCS) for the (e,2e) process on H2O molecule for the plane wave
and the twisted electron beam impact. The formalism is developed in the first
Born approximation. We describe the plane/twisted wave, plane wave, the linear
combination of atomic orbitals (LCAO) (self-consistent field LCAO method) and
Coulomb wave for the incident electron, scattered electron, the molecular state
of H2O, and the ejected electron, respectively. We investigate the angular
profiles of the TDCS for the outer orbitals 1B1, 3A1, 1B2, and 2A1 of the water
molecule. We compare the angular profiles of the TDCS for the different values
of orbital angular momentum (OAM) number m of the twisted electron beam with
that of the plane wave beam. We also study the TDCS for macroscopic H2O target
to explore the effect of opening angle {\theta}p of the twisted electron beam
on the TDCS. Our results clearly show the effect of the twisted electron's OAM
number (m) and the opening angle {\theta}p on the TDCS of the water molecule.
