  This article reports the study of SnO by using the first-principles
pseudopotential plane-wave method within the generalized gradient approximation
(GGA). We have calculated the structural, elastic, electronic and optical of
SnO under high pressure. The elastic properties such as the elastic constants
Cij bulk modulus, shear modulus, Young modulus, anisotropic factor, Pugh ratio,
Poisson ratio are calculated and analyzed. Mechanical stability of SnO at all
pressure are confirmed by using Born stability criteria in terms of elastic
constants and are associated with ductile behaviour based on G/B ratios. It is
also found that SnO exhibits very high anisotropy. The energy band structure
and density of states are also calculated and analyzed. The results show the
semiconducting and metallic properties at 0 (zero) and high pressure,
respectively. Furthermore, the optical properties such as dielectric function,
refractive index, photoconductivity, absorption coefficients, loss function and
reflectivity are also calculated. All the results are compared with those of
the SnO where available but most of the results at high pressure are not
compared due to unavailability of the results.
