Table 1 Experimental and calculated structural parameters of CdCl2- and CdI2-type phases of MgCl2 at selected pressures.

From: High-pressure X-ray diffraction, Raman and computational studies of MgCl2 up to 1 Mbar: Extensive pressure stability of the β-MgCl2 layered structure

P(GPa)

SG

Z

a(Å)

c(Å)

Vpfu(Å3)

Ko(GPa)

K′

WP

x

y

z

0

R-3m

3

3.635(1)

17.608(3)

67.16(2)

38.5(1.6)

4(fixed)

Cl(6c)

0

0

0.2557(2)

0 (calc.)

R-3m

3

3.651

17.785

68.44

22.7(0.4)

5.6(0.1)

Cl(6c)

0

0

0.2574

013

 

3

3.6263

17.6663

67.43

  

Cl(6c)

0

0

0.2578

9.8

P-3m1

1

3.472(5)

5.212(4)

54.33(7)

32.3(1.9)

4.3(0.3)

Cl(2d)

1/3

2/3

0.264(3)

9.8 (calc.)

P-3m1

1

3.4567

5.2388

54.211

27.6(0.5)

4.7(0.1)

Cl(2d)

1/3

2/3

0.2604

10.111

FeCl2

1

3.4188

5.221

52.85

35.3(1.8)

4(fixed)

Cl(2d)

1/3

2/3

0.270

  1. Listed parameters include space group (SG), number of formula units in the unit cell Z, lattice parameters, cell volume per formula unit, bulk modulus Ko and the pressure derivative K′ as determined by unweighted least square fits and the Wyckoff site with corresponding coordinates. Theoretical values (calc.) are listed below experimental values. Corresponding values from ref. 13 for MgCl2 at ambient pressure and from ref. 11 for FeCl2 at 10.1 GPa are provided for comparison.
Back to article page