The analytic energy gradients in combined second order Møller- Plesset perturbation theory and conductorlike polarizable continuum model calculations are derived and implemented for spin-restricted closed shell (RMP2), Z-averaged spin-restricted open shell (ZAPT2), and spin-unrestricted open shell (UMP2) cases. Using these methods, the geometries of the S 0 ground state and the T1 state of three nucleobase pairs (guanine-cytosine, adenine-thymine, and adenine-uracil) in the gas phase and aqueous solution phase are optimized. It is found that in both the gas phase and the aqueous solution phase the hydrogen bonds in the T1 state pairs are weakened by ∼1 kcalmol as compared to those in the S0 state pairs.
ASJC Scopus subject areas
- Physics and Astronomy(all)
- Physical and Theoretical Chemistry