Savant

Out of curiosity, where did GEOCENTRIC obtain this formula?

I agree with UncleA1 -- sort of. There is a relationship between density and refractive index. Clearly the actual refractive index of bromine at near vacuum is less than liquid bromine. The published (standardized) refractive index of bromine is a refractive index measured at standard conditions thus eliminating density variance. The same can be said of any other material and comparison of refractive indexes of varying materials are also taken at standard conditions that do not permit an easy comparison of density effects.

I look forward to communicating with all you folks.