There are two possible electron domain geometries (linear and trigonal bi-pyramidal).
Work Step by Step
There are two bonded atoms with a bond angle of 180 degrees, so we know that the shape is linear. One possibility is that there are no lone electron pairs, which would mean that there is a linear electron geometry. However, it is also possible for there to be a linear molecular geometry with two bonded atoms and three electron pairs. This would result in a trigonal bi-pyramidal electron geometry.