Our main objective in this proposal is to study the competition between halogen and hydrogen bonding as a function of temperature in the complex (CH3)2C=O--- Br2. The results of a previous experiment on HRPD has shown that, in addition to a halogen bond between the carbonyl group and bromine molecule, there is an unusual C-H----O=C hydrogen bond which, unlike most other bonds of this type, is almost at right angles to the plane of the carbonyl group, rather than being coplanar. In addition to the PND study we have also carried out single crystal XRD studies at two temperatures (220, 110K) which showed that the C=O---Br halogen bond in the complex (CH3)2C=O becomes stronger upon decreasing the temperature. Studies as a function of temperature will shed light on the interplay of these intermolecular bonds in determining the structure of this and similar materials.