  The topological Weyl semimetal MoTe2, in the orthorhombic phase, is an
important system both from the point of view of fundamental physics and
potential applications. In this study we have investigated the elastic,
electronic, bonding and optical properties of MoTe2 using density functional
theory. Study of the elastic constants and moduli indicates that MoTe2 is a
relatively soft material with high level of machinability. Mechanical stability
conditions are fulfilled. The compound possesses elastic and mechanical
anisotropy and is prone to brittle fracture. Elastic parameters indicate that
both covalent and metallic bondings are present in MoTe2. This is supported by
the charge density distribution mapping and Mulliken and Hirshfeld bond
population analyses. Debye temperature has been calculated. A relatively low
value of Debye temperature also supports the scenario where bonding strengths
are weak. The bulk electronic band structure calculations reveal clear
indications of semi-metallic character. A pseudogap in the electronic energy
density of states at the Fermi level indicates high level of electronic
stability. Features reminiscent of the Dirac cone is observed close to the
Fermi level. There is significant electronic anisotropy. Bands running in the
crystallographic c-direction are non-dispersive with high carrier effective
mass. Investigation of optical constants demonstrate that MoTe2 possess
excellent reflecting characteristics over a wide spectral range encompassing
the infrared to ultraviolet regions. The compound also has high refractive
index in the visible range. MoTe2 is optically anisotropic, reflecting the
anisotropic nature of the electronic band structure. The energy dependent
optical parameters show metallic features and are in complete accord with the
electronic density of states calculations.
