[ccp4bb] Cavity filling

[Simon Kolstoe]

Dear ccp4bb

A structure I have recently finished has a cavity with four waters in  
it. I am wondering if I might be able to fit a small molecule in the  
same place. Does anyone know a way of making some type of map of this  
cavity and then searching through a small molecule library to see what  
might fit in it (I'm guessing there is commercial software that will  
do this however I am after something without large financial  
commitments!)?

Thanks,

Simon