Modelled Raman enhancements around two silver nanoparticles of radius 50nm, separated by 1nm and illuminated with radiation of wavelength 514nm. The inset shows an enlarged portion of the main picture, around the area between the nanoparticles. The colours in red are the areas of highest Raman enhancement and those in blue are the areas of lowest Raman enhancement.  A maximum enhancement of approximately 10<SUP>7</SUP> is predicted.