Table 1 Refined structural parameters for vaterite and calcite in Lake Sturgeon otoliths using neutron powder diffraction data from NOMAD 31°, 67°, and 122° detector banks (CIF available in supplementary materials).

From: Empirically testing vaterite structural models using neutron diffraction and thermal analysis

Atom

Wyckoff site

Symmetry

x

y

z

UisoÅ2

vaterite phase, space group P6522 a = 7.1443(4), c = 25.350(4) Å, V = 1121.5(2)Å3

Ca1

6b

2

0.007(2)

−x

1/12

0.009(3)*

Ca2

6b

2

0.681(2)

−x

1/12

0.009(3)*

Ca3

6b

2

0.343(2)

−x

1/12

0.014(8)

C2

6a

2

0.691(2)

0

1/2

0.027(4)

O1

6a

2

0.859(2)

0

1/2

0.027(4)

O2

12c

1

0.602(1)

−0.008(3)

0.5409(4)

0.027(4)

C1

12c

1

0.375(2)

0.327(2)

0.1658(3)

0.024(2)

O3

12c

1

0.556(2)

0.337(3)

0.1714(5)

0.024(2)

O4

12c

1

0.270(2)

0.326(3)

0.2059(4)

0.024(2)

O5

12c

1

0.300(2)

0.317(3)

0.1201(4)

0.024(2)

calcite phase, space group Rc a = 4.9856(6), c = 17.046(3)Å, V = 366.94(9) Å3

Ca

6b

0

0

0

0.004(2)

C

6a

32

0

0

1/4

0.014(2)

O

18e

2

0.2607(8)

0

1/4

0.013(1)

  1. Atoms C2, O1, O2 and C1, O3, O4, O5 constitute the rigid bodies C2 and C1, respectively.
  2. *The isotropic U’s for Ca1 and Ca2 were constrained to be the same, otherwise the least squares would not converge.
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