A new method for determining the structure of aqueous electrolyte solution using θ-2θ type powder diffractometer has been developed. The thermostatic super-thick liquid sample cells have been designed and the correction procedures for the diffraction intensity of window on the cell proposed. A very satisfactory experimental result of molten salt of hexaquamanganese nitrate has been obtained. A comparison between the raidal distribution function curve with the θ- 2θ type diffractometer and that with the θ-θ type diffractometer by the free surface scattering shows that the resolution has improved to some extent. The hydrogen bonding distance of 0.28nm from the cis-O-O interaction of 0.31nm in the first coordination shell in the octahedral compllex ion of [Mn(H2O)5(ONO2)]^+ and the Mn-N distance of 0.309nm in the contact ion pair have been clearly distinguished. Then the Mn-O(II) peak at 0.42nm from the trans-O-O peack at 0.44nm has been separated out. With the improvement of the resolution, some ripples occured in the high r zone. This is to be overcome.

Key words: POWDER DIFFRACTOMETER, DISTRIBUTION FUNCTION, ELECTROLYTE, AQUEOUS SOLUTION, LIQUID STRUCTURE