Theoretical studies of the dependence of nuclear quadrupole coupling constants on intermolecular forces

► Nuclear quadrupole coupling constants (NQCCs) are studied at DFT and MP2 levels. ► For uracil and thymine we compare DFT, ab initio and experimental values. ► We select three functionals and focus on intermolecular interactions. ► There are large effects of proton transfer on NQCC in DNA base pairs. ► The computed changes of NQCC do not depend significantly on the approximation.