Static first order hyperpolarizabilities of DNA base pairs: A configuration interaction study

We have investigated the role of H-bonding on the static first-order hyperpolarizabilities of DNA base pairs, namely, adenine-thymine (AT) and guanine-cytosine (GC). To interpret the effect of long-range dipolar interaction on this optical coefficient, the configuration interaction method has been implemented in these systems. Remarkably, the static first-order hyperpolarizability values gradually increases for the AT base pair as one increases the H-bonding distance between the DNA bases, whereas a reverse trend is observed for the GC base pair where the hyperpolarizability values pass through a minimum.