A 0.9-5.6µm model transmission spectrum of the atmosphere over Cerro Pachon is available (as a 4.9MB text file) here. The spectrum is for an airmass of 1.5 and for 7.6 mm of water (thus somewhat non-optimal conditions at wavelengths where H2O is important). The resolution is 0.00004µm, roughly comparable to the resolution of Phoenix (somewhat lower near 1µm and somewhat higher near 5µm. The wavelength scale is in vacuo.