The vibrational OH stretch spectra have been measured for the size-selected pure water clusters (H2O)(7). In contrast to (H2O)(n), n = 8-10 clusters, which exhibit three distinct bands corresponding to three distinct types of OH bonds, the heptamer spectrum displays seven bands spanning the range from 2935 to 3720 cm(-1). Calculations suggest that the spectra originate from two isomers, derived from the S-4 octamer cube by removal of either one double donor or one double acceptor water molecule.