The project is concerned with atomic physics properties and with the macroscopic behaviour of hot and dense plasmas produced by the collision of two foils accelerated by laser beams. The transient ionic molecules formed in these highly correlated and highly ionised environments have their own specific spectral signatures on the line profiles. These signatures can be exhibited only if the collision is sufficiently planar and if the plasmas properties include it being dense and emissive. Laser-matter interaction experiments will be carried out in order to analyse the effects of the spatial and temporal laser beam profiles on the emitted spectra: producing flat top focal spots will give rise to higher plasma densities with improved planar quality, resulting in better spectral and spatial accuracies. These experiments will be driven by numerical simulation; the spectra will be interpreted by means of spectral profile codes accounting for monocenter ions and transient molecules emission.