  We systematically study the pristine and doped chromium arsenide (CrAs) in
six different crystal structures to investigate the structural, magnetic, and
optical properties for real applications by first-principles calculations.
First, we found that the ground-state structure is an orthorhombic MnP-type
structure with antiferromagnetic spin order. The rocksalt structure is an
low-energy metastable phase and a ferromagnetic metal with high spin
polarization at the Fermi level. Secondly, the NiAs structure and MnP structure
have a higher absorption coefficient than other structures in the infrared
region and ultraviolet region, respectively. In the visible light region, the
wurtzite and zincblende structures are more transparent than other structures.
At last, we found that Ti substitution of Cr and Te substitution of As can lead
to a phase transition in ground-state structure and ground-state magnetic
order, respectively. These results can promote the application of the CrAs
system into spintronics.
