Let's say I have a trigonal prism in my crystal structure and this is further capped by two ions it's called a bicapped trigonal prism. If I have three ions it's called a tricapped trigonal prism. But what about four? I cannot find anything like quadcapped, fourcapped, fourfold capped trigonal prism. How would you name that?
After asking more people who already wrote reports with similar structures and a paper I found on the net the most convincing answer I could find was the term 'tetracapped'.