It has been drawn to the authors’ attention that our original article[1] did not appropriately attribute some figures that we had reused or adapted from our own previous work. The figure captions as they should have appeared follow. Figure 1. A Kohn-Sham orbital for an oligopeptide molecule: in general, each orbital extends over the entire system. Reproduced with permission[12] (from Figure 1 of ref. 12). Copyright 2005, American Institute of Physics. Figure 2. Three localised orbitals (non-orthogonal generalised Wannier functions) generated by ONETEP for the same oligopeptide molecule as Figure 1. Reproduced with permission[12] (from Figure 1 of ref. 12). Copyright 2005, American Institute of Physics. Figure 4. Total energy convergence with respect to density-kernel cut-off rK for a Ti38O76 cluster. Adapted with permission.[46] Copyright IOP Publishing. Figure 5. A single NGWF centred on one carbon atom of an ethene molecule before (left) and after (right) optimisation in ONETEP. Adapted with permission.[34] Copyright 2002, American Physical Society. Figure 9. Energy (inset RMS gradient) convergence of the NGWF optimisation for a variety of systems – figures in parentheses in legend indicate number of atoms. Data from ref. 57. Figure 10. Interaction potentials (negated binding energies) for a hydrogen-bonded water dimer. Data from ref. 60. Cited references from [1]: