Citation: Thompson, R. M.; Downs, R. T. (2004). Model pyroxenes II: Structural variation as a function of tetrahedral rotation model spodumene at 3.164 GPa after Arlt and Angel (2003) with O3-O3-O3 angle = 189.5 and model oxygen radius = 1.254. American Mineralogist, 89, pp. 614-628.