Extracting Coupling Capacitance between unconnected cells

 Hi All,

 I am trying to figure out the impact (in terms of measurable delays in static timing analysis) do unconnected (standard) cells have on each other. To start with, I have a design, and I am inserting additional ('spare') cells, and leaving them unconnected.

Next, I extract RC, and run timing analysis (report_timing ...)

I do not see any changes in the timing values reported. 

Is it possible to extract this kind of information during static timing analysis stage? I do not have access to Fire-n-Ice extractor ( I get an error mentioning that an executable was not found).

If extracting timing variations due to coupling capacitances is possible during the static timing analysis phase, I will appreciate, if someone can please show me where (and how) to start.

Thanks a lot for your time!

Sirrius