Calculation of potential energy surfaces using explicitly correlated methods

Recent developments in explicitly correlated wavefunctions mean that highly accurate potential energy surfaces for small molecules can be obtained with a low computational cost. Key components of these composite surfaces will be presented, including extrapolation of explicitly correlated CCSD(T) correlation energies and correcting for core-valence correlation effects using F12 methods. Recent applications will be highlighted, including high-resolution spectroscopy of CCN, CCO$^{+}$ and COC$^{+}$.