Some questions about the description of the comman multisphere

The first question is about the [compute multisphere command], since I know the properties of the given multisphere template have been caculated by Monte Carlo method before the simulation, I have tried to use the [compute multisphere command] to get the properties. I add the [compute dens all multisphere property density] to the given example "multisphere_stone_restitution". But there is always an error : invalid compute style. I want to konw why this simple command does not take effect. Does any body have a simple example to show me ? Or I have neglect some restrictions mentioned elsewhere?

The second question is about the [use_volume] opt_keyword following the [fix particletemplate/multisphere command], I wonder which kind is the volume in effect. For Example, I use several overlapping spheres to get a multisphere which reprensents a irregular particle, there are two kinds of volume ,first is the sum of each sphere volume,second is the particle volume which ignore the overlapping region. which volume will be in effect when using opt_keyword [use_volume] .