D_{3h} T240

Unlike the TCNTs we constructed before, this one is obtained by extending the edges of one Schwartz-H graphenoid unit cell. In other hand, it can be realized as retracting three nonadjacent "arms" of the normal type D_{6h} TCNT 'till twelve pairs of 5/7-gons meet and merge into six pairs of 4/8-gons...