double planet orbits

[Zadukk]

I'm experimenting with double planet systems.

I know how to calculate mean distances to center of mass. What I'm not so sure about is orbit eccentricity : is it the same for both planets? If not, how can one be calculated from the other?

[Hungry4info]

Yes, the eccentricity will be the same, and the longitude of perihelion will be opposite (180 degrees) of each other.

[Zadukk]

Thanks

[Hungry4info]

Thanks

Any time