Effect of extra-framework cations on negative linear compressibility and high-pressure phase transitions: A study of KCd[Ag(CN)2]3 by Cairns, AB, Catafesta, J, Hermet, P, Rouquette, J, Levelut, C, Maurin, D, van der Lee, A, Dmitriev, V, Bantignies, J-L, Goodwin, AL, Haines, J