  Theoretical studies predicted possible superconductivity in electron-doped
chromium pnictides isostructural to their iron counterparts. Here, we report
the synthesis and characterization of a new ZrCuSiAs-type Cr-based compound
ThCrAsN, as well as its oxygen-doped variants. All samples of
ThCrAsN$_{1-x}$O$_x$ show metallic conduction, but no superconductivity is
observed above 30 mK even though the oxygen substitution reaches 75\%. The
magnetic structure of ThCrAsN is determined to be G-type antiferromagnetic by
magnetization measurements and first-principles calculations jointly. The
calculations also indicate that the in-plane Cr--Cr direct interaction of
ThCrAsN is robust against the heavy electron doping. The calculated density of
states of the orbital occupations of Cr for ThCrAs(N,O) is strongly
spin-polarized. Our results suggest the similarities between chromium pnictides
and iron-based superconductors shouldn't be overestimated.
