Are you really sure you want a static instance of the struct at global scope? You may run in to issues regarding the initialization order of such and other of your objects, and should therefore thread forth with extreme caution.
Typically, you would define a class in one file (a .h), implement it in another (a .cpp), then include the definition in another .h or .cpp. To access data within it, you create instances of the struct, in this case e.g. as sVData sData, then refer to the members with sData.i.