- The development of new computational methods for the calculation of molecular properties, in particular linear and nonlinear properties involving mixed electric and magnetic fields, as well as perturbations due to nuclear distortions.
- The understanding of linear and nonlinear magnetic and chiroptical properties of molecules.
- Small effects on molecular properties, such as vibrational corrections, solvent effects, and relativistic corrections using a variety of approaches.
- Vibronic effects on molecular properties.
- Multiwavelets as basis functions in quantum chemical calculations.
- Nuclear Shielding Constants of Liquid Water. Insights from Hybrid Quantum Mechanics/Molecular Mechanics Models. J.Kongsted, C.B.Nielsen, K.Aidas, K.V.Mikkelsen, O.Christiansen and K.Ruud. J.Chem.Phys. 126, 034510 (2007)
- Can Raman optical activity separate axial from local chirality? A theoretical study of helical deca-alanine. C.Herrmann, K.Ruud, and M.Reiher. ChemPhysChem 7, 2189 (2006).
- Superlinear scaling in master-slave quantum chemical calculations using in-core storage of two-electron integrals. E.Fossgaard and K.Ruud. J.Comput.Chem. 27, 326 (2006)
- Second-harmonic generation of solvated molecules using MCSCF quadratic response theory and the polarizable continuum model. L.Frediani, H.Ågren, L.Ferrighi and K.Ruud, J.Chem.Phys.123, 144117 (2005)
- The importance of molecular vibrations: The sign change of the optical rotation of methyloxirane. K.Ruud and R.Zanasi, Angew.Chem.Int.Ed. 44, 3594 (2005).