In A+B- ionic compound, radii of A+ and B- ions are 180 pm and 187 pm respectively. The crystal structure of this compound will be

r+/r-=180187=0.962 which lies in the range of 0.732 - 1.000, hence coordination number = 8, i.e. the structure is CsCl type( Cubic arrangement)ie.,cubic void is occupied by cation.