Equation of state of hollandite type-structure

Abstract
The room-temperature compression of BaFeMn7O16hollandite has been determined to 519 kbar with X-Ray methods. With a 1-bar molar volume of V0=339±2 cm3/mol and a Birch-Murnaghan equation of state, we obtain for the bulk modulus K'0=2304±150 kbar and for the pressure derivative K'0=1.73±0.45.If these moduli are typical of a hollandite structure, then the high-pressure density of the Ca0.5Mg0.5Al2Si2O8pseudo-hollandite could be similar to those of silicates with a perovskite structure.