In a previous paper we reported the formation of the gallium‐Xcenter by neutron irradiation of gallium‐doped silicon. Since that report we have investigated a variety of other neutron‐irradiated Si:Ga samples using float‐zone crystals grown by three different vendors and irradiated at four different reactors. The behavior of Ga‐Xas a function of irradiation conditions, annealing temperatures (up to 800 °C) and various material properties has been studied by Fourier‐transform infrared absorption spectroscopy and temperature dependent Hall‐effect measurements. Ga‐Xwas not observed in any of the as‐grown samples but was definitely present in every irradiated sample. In all cases it first appears after a 400 °C anneal, reaches maximum concentration after a 600 °C anneal, and then decreases at higher anneal temperatures. The maximum Ga‐Xconcentration observed in any sample appears to be dependent on the carbon concentration in that sample and not on the irradiation conditions. A more detailed Ga‐Xabsorption spectrum was obtained showing lines not previously reported. A binding energy of 57.18±0.03 meV is deduced for the Ga‐Xground state.