The prediction of the effects on the dielectric constant in thin film dielectrics is of interest in a variety of electronic applications ranging from microelectronics to displays and MEMS applications. This paper discusses the link between the molecular structure of a silicate spin-on dielectric and the final processed dielectric constant by relating trends in the calculated dielectric constant using Density Functional Theory to measurements made on thin films produced during formulation and cure studies. For this investigation, silanol and water content, film density and stress were varied both computationally and experimentally in order to understand the trade-off contributing toward the final dielectric constant. It was found that there is a non-trivial relationship between all these variables which relates back to the molecular structure of the final material, expressed by the density and the stress state of the material. This underlines the importance of finding stable processes in order to produce reproducible films.