  The magnetic tetrapyrrole molecules (such as porphyrins and phthalocyanines)
with an active transition metal atom in their centre are currently intensively
studied as prosperous potential elements of devices for high-density
information storage and processing. It has been recently proved that by means
of external factors one could induce two stable fully controllable molecular
states. Therefore, hybrid systems consisting of such magnetic molecules and
suitable carriers from the family of two-dimensional materials are often
considered as promising highly scalable spintronic systems that could in the
near future lead to novel industrial applications. Here, we perform the spin
polarised density functional theory (DFT) studies of the hybrid system, which
is the iron phthalocyanine molecule (FePc) on the top of the titanium carbide
Ti$_2$C MXene layer. The most relevant issue in this part is the interaction
between magnetic atoms: Ti from MXene substrate and iron from FePc. Four
various magnetic configurations of FePc/Ti$_2$C were considered. The
significant ferromagnetic interaction between the iron atom and the upper
titanium layer plays important role in the reorientation of the iron atom's
magnetic moment. We also analyse a model of the system in which the FePc
molecule is in a quintet state (the ground state of an isolated molecule is a
triplet). To get a better understanding of the physics of the FePc/Ti$_2$C
hybrid system, we studied the hybrid systems with a single iron atom and
non-magnetic H$_2$Pc on the Ti$_2$C layer, Fe/Ti$_2$C and H$_2$Pc/Ti$_2$C,
respectively, which nicely explains the role of the Pc ligand in the
FePc/Ti$_2$C hybrid system.
