In my A level chemistry textbook, there is a picture of a table where the silver halides have a less negative value for lattice energy (that has been calculated theoretically) compared to the more negative value (calculated from a born Haber cycle). I know that is because of Polarization, however why do they say that the silver halides are much more stable than what a purely ionic model suggests? Are they saying that a less negative value for lattice energy suggests that it is more stable? Why is that?