Citation: Thompson, R. M.; Downs, R. T. (2004). Model pyroxenes II: Structural variation as a function of tetrahedral rotation model low clinoenstatite after Pannhorst (1984) with O3A-O3A-O3A angle = 202.8, O3B-O3B-O3B angle = 138.1, and model oxygen radius = 1.306. American Mineralogist, 89, pp. 614-628.