Structures of DNA adenine-thymine fragments as used in the following
publication:

 - B. Doser, D. S. Lambrecht, J. Kussmann, and C. Ochsenfeld;
   Linear-scaling atomic orbital-based second-order Møller-Plesset perturbation
   theory by rigorous integral screening criteria,
   J. Chem. Phys. 130, 064107 (2009).

The original structures have been obtained by the Spartan package.
