The structures, isomerization and spectroscopies of GeSiN and GeCP radicals are explored at density functional theory and ab initio levels. For GeSiN, the global minimum is linear GeNSi 1, in agreement of the mass spectra detection, which can be qualitatively described as a resonance hybrid of vertical bar Ge=N vertical bar-Si vertical bar center dot and center dot vertical bar Ge-N vertical bar=Si vertical bar, where the latter contributes more. As to GeCP, the lowest-lying isomer is linear GeCP 1 resonating between center dot vertical bar Ge-C P vertical bar and vertical bar Ge=C=P vertical bar center dot with the former contributes more, followed by a cyclic isomer cGeCP 2 at 8.8 kcal/mol. All above three species with large kinetic stability (about 10 kcal/mol barrier) should be experimentally important. (C) 2010 Elsevier B.V. All rights reserved.