  Recently, three-component new fermions in topological semimetal MoP are
experimentally observed, which may have potential applications like topological
qubits, low-power electronics and spintronics. These are closely related to
thermal transport properties of MoP. In this work, the phonon transport of MoP
is investigated by solving the linearized phonon Boltzmann equation within the
single-mode relaxation time approximation (RTA). The calculated
room-temperature lattice thermal conductivity is 18.41 $\mathrm{W m^{-1}
K^{-1}}$ and 34.71 $\mathrm{W m^{-1} K^{-1}}$ along the in- and cross-plane
directions, exhibiting very strong anisotropy. The isotope and size effects on
the lattice thermal conductivity are also considered. It is found that isotope
scattering produces little effect, and phonon has little contribution to the
lattice thermal conductivity, when phonon mean free path(MFP) is larger than
0.15 $\mathrm{\mu m}$ at 300 K. It is noted that average room-temperature
lattice thermal conductivity of MoP is lower than that of representative Weyl
semimetal TaAs, which is due to smaller group velocities and larger
Gr$\mathrm{\ddot{u}}$neisen parameters. Our works provide valuable informations
for the thermal management of MoP-based nano-electronics devices, and motivate
further experimental works to study thermal transport of MoP.
