Encyclopedia of Crystallographic Prototypes

AFLOW Prototype: A_cI16_220_c-001

This structure originally had the label A_cI16_220_c. Calls to that address will be redirected here.

If you are using this page, please cite:
M. J. Mehl, D. Hicks, C. Toher, O. Levy, R. M. Hanson, G. L. W. Hart, and S. Curtarolo, The AFLOW Library of Crystallographic Prototypes: Part 1, Comp. Mat. Sci. 136, S1-S828 (2017). (doi=10.1016/j.commatsci.2017.01.017)

Links to this page

https://aflow.org/p/BTF5
or https://aflow.org/p/A_cI16_220_c-001
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High-pressure cI16 Li Structure: A_cI16_220_c-001

Prototype	Li
AFLOW prototype label	A_cI16_220_c-001
ICSD	109012
Pearson symbol	cI16
Space group number	220
Space group symbol	$I \overline{4} 3 d$
AFLOW prototype command	aflow --proto=A_cI16_220_c-001 --params= $a, x_{1}$

This is a high-pressure phase of lithium. We use the data from (Hanfland, 2000) at 38.9 GPa. When $x_{1} = 0$ this becomes a body-centered cubic ( $A 2$ ) system.
We have used the fact that all vectors of the form $(\pm a /2 \overset{x}{^} \pm a /2 \overset{y}{^} \pm a /2 \overset{z}{^})$ are primitive vectors of the body-centered cubic lattice to simplify the positions of some atoms in both lattice and Cartesian coordinates.
The ICSD entry was recorded at 45 GPa.

a_{1} a_{2} a_{3} = = = - \frac{1}{2} a \hat{x} + \frac{1}{2} a \hat{y} + \frac{1}{2} a \hat{z} \frac{1}{2} a \hat{x} - \frac{1}{2} a \hat{y} + \frac{1}{2} a \hat{z} \frac{1}{2} a \hat{x} + \frac{1}{2} a \hat{y} - \frac{1}{2} a \hat{z}

Picture of Structure; Click for Big Picture

Basis vectors

		Lattice coordinates		Cartesian coordinates	Wyckoff position	Atom type
$B_{1}$	=	$2 x_{1} a_{1} + 2 x_{1} a_{2} + 2 x_{1} a_{3}$	=	$a x_{1} \hat{x} + a x_{1} \hat{y} + a x_{1} \hat{z}$	(16c)	Li I
$B_{2}$	=	$\frac{1}{2} a_{1} - (2 x_{1} - \frac{1}{2}) a_{3}$	=	$- a x_{1} \hat{x} - a (x_{1} - \frac{1}{2}) \hat{y} + a x_{1} \hat{z}$	(16c)	Li I
$B_{3}$	=	$- (2 x_{1} - \frac{1}{2}) a_{2} + \frac{1}{2} a_{3}$	=	$- a (x_{1} - \frac{1}{2}) \hat{x} + a x_{1} \hat{y} - a x_{1} \hat{z}$	(16c)	Li I
$B_{4}$	=	$- (2 x_{1} - \frac{1}{2}) a_{1} + \frac{1}{2} a_{2}$	=	$a x_{1} \hat{x} - a x_{1} \hat{y} - a (x_{1} - \frac{1}{2}) \hat{z}$	(16c)	Li I
$B_{5}$	=	$(2 x_{1} + \frac{1}{2}) a_{1} + (2 x_{1} + \frac{1}{2}) a_{2} + (2 x_{1} + \frac{1}{2}) a_{3}$	=	$a (x_{1} + \frac{1}{4}) \hat{x} + a (x_{1} + \frac{1}{4}) \hat{y} + a (x_{1} + \frac{1}{4}) \hat{z}$	(16c)	Li I
$B_{6}$	=	$\frac{1}{2} a_{1} - 2 x_{1} a_{3}$	=	$- a (x_{1} + \frac{1}{4}) \hat{x} - a (x_{1} - \frac{1}{4}) \hat{y} + a (x_{1} + \frac{1}{4}) \hat{z}$	(16c)	Li I
$B_{7}$	=	$- 2 x_{1} a_{1} + \frac{1}{2} a_{2}$	=	$a (x_{1} + \frac{1}{4}) \hat{x} - a (x_{1} + \frac{1}{4}) \hat{y} - a (x_{1} - \frac{1}{4}) \hat{z}$	(16c)	Li I
$B_{8}$	=	$- 2 x_{1} a_{2} + \frac{1}{2} a_{3}$	=	$- a (x_{1} - \frac{1}{4}) \hat{x} + a (x_{1} + \frac{1}{4}) \hat{y} - a (x_{1} + \frac{1}{4}) \hat{z}$	(16c)	Li I

References

M. Hanfland, K. Syassen, N. E. Christensen, and D. L. Novikov, New high-pressure phases of lithium, Nature 408, 174–178 (2000), doi:10.1038/35041515.

Encyclopedia of Crystallographic Prototypes

High-pressure cI16 Li Structure: A_cI16_220_c-001

Body-centered Cubic primitive vectors

References

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