spectrometry is not suitable for the determination of the regular hydroxyl radical oh due to large amounts of hydrogen in the clbo crystal caused by absorption of atmospheric water due to a low natural abundance of the deuterium atom such atmospheric water absorption will not affect deuterium detection sensitivity substitution of water with heavy water can also result in a reduced effect on clbo crystal growth and properties first deuterium substituted compounds are known to sometimes display substantially different chemical reactivity consequently the formation rate and thermal stability of deuterium oxide in the melt may be less than that of hydroxide which results in a more pure clbo crystal the penetration of deuterium oxide into the clbo crystal during the growth is also expected to be different second because of the lower vibrational energy potential vibronic interactions are weaker for clbo crystals with deuterium oxide impurities in comparison to clbo crystals that are contaminated with hydroxide this reduces vibrationally assisted absorption and can improve ultraviolet transmission especially at elevated temperatures and wavelengths that are close to the band gap value or less than about 200 nanometers the foregoing description of embodiments for this invention has been presented for purposes of illustration and description it is not intended to be exhaustive or to.