Basis sets developed using the generator coordinate method and a pseudopotential have been adapted to density functional theory to calculate the proton affinity of GeH4, GeH3-, GeF3-, CH3GeH2-, and Ge(OH)(3)(-) and the electron affinity of .GeH3 and .GeF3. The proton affinity of GeH4 is calculated to be 673.9 kJ mol(-1) at 298 K, while values for GeH3- (1505.0 kJ mol(-1)) and CH3GeH2- (1529.0 kJ mol(-1)) are in excellent agreement with experimental values. The electron affinity of .GeF3 is predicted to be in the range of 3.5-3.7 eV by calculations using different functionals and ab initio methods. The present calculations reveal that the B3P86 method can yield proton affinities comparable to those obtained with other high-quality methods but consistently overestimates electron affinities of simple Ge radicals.