The liquid (water) contracts from 0 to 4°C and then expands at 1 bar (atmospheric conditions). There is liquid-liquid phase transition at 4°C. The websites may provide all the information related to your queries.
The volume of water decreases by about 9% when it is melting at 0oC under normal atmospheric pressure. The structure of ice is open with a low packing efficiency where all the water molecules are involved in four straight tetrahedrally-oriented hydrogen bonds. On melting, some of the ice bonds break, others bend and the structure undergoes a partial collapse.