Transfering to ANSYS

Thanks for your best efforts.I generated a CNT of my desired dimension using supercell method but after converting the pdb file into txt file and transferring into ANSYS produces an image rather than CNT(see image 1 and 2).

But when creating CNT directly using non periodic tube structure and converting this pdb file into txt and then transferring into ANSYS produces perfect CNT(see image 3).

Kindly tell me why the 1st method is not generating  a perfect CNT while the 2nd one does pretty well in ANSYS.

Please tell me a solution for this.

Thank You