Calculate the net force that thymine exerts on adenine. To keep the calculations fairly simple, yet reasonable, consider only the forces due to the O−H−NO−H−N and the N−H−NN−H−N combinations, assuming that these two combinations are parallel to each other. Remember, however, that in the O−H−NO−H−N set, the O−O− exerts a force on both the H+H+ and the N−N−, and likewise along the N−H−NN−H−N set.