The Quantum Bio-Inorganic 91AV series of international meetings focuses on computational inorganic and bioinorganic chemistry including emerging theoretical methods and novel applications. QBIC•IV follows the popular and successful QBIC meetings in Warwick (UK, 1999), Lund (SE, 2003) and Český Krumlov (CZ, 2011) and continues to provide a showcase for the latest developments and applications presented by both internationally-renowned and early-career researchers. We look forward to welcoming you in the beautiful World Heritage city of Bath for QBIC•IV.