General question regarding Amorphous Cell

Hi,

I am new user. I am 'playing' with AC trying to simulate conducting polymer blends.

I am using MS 5.0. Can someone explain me the difference between Calculation and Construction (Legacy) tool. Interfaces look different, but both tool do pretty much the same job - they are used to build a cell filled with (in my case) conducting polymers.

If I am right, why there is 2 tools to do the same job? When should I use 'Calculation' when 'Construction' tool?

Cheers,

Bart