Matrix effects on the optical spectra of alkali atoms trapped in Ar, Kr and Xe matrices: a pseudopotential calculations

By a pseudopotential method the perturbation of the outer electronic s and p levels of Na and K by rare gas matrices is calculated. It is concluded that the stable trapping site consists of four vacancies, except for a substitutional site for Na in Xe. A metastable site of three vacancies gives the ''red triplet'' in the absorption spectrum.