Phase

copper

tenorite

“siemonsite”

cuprite

paramelaconite

Formula

Cu

CuO

T-CuO

Cu2O

Cu4O3-x

Space group

Fm3m

C2/c (293 K)

Pn3m

I41/amd

a (Å)

3.6147

4.6837

3.905

4.2696

5.837

b (Å)

3.4226

c (Å)

5.1288

5.30

9.932

β (°)

99.54

V (Å3)

81.080

80.82

77.832

4 × 84.598

ρ (kg/m3)

8.937

6.516

6.54

6.106

5.93

Cu-Cu (Å)

2.5560

2.9005

3.0830

3.1733

2.761

3.0191

2.9185

ε

5.9 || [010]

6.2 || [101]

7.8 ||

7.11 ε(0)

6.46 ε(∞)

4.24 ε(∞)*

ΘD (K)

347 (0 K)

310 (298 K)

391

188

vs (m/s)

4.76 × 103

longitudinal

2.33 × 103

transverse

6.4 × 103 [100]

4.1 × 103 [010]

7.8 × 103 [001]

5.4 × 103 [101]

9.1 × 103

6.8 × 103 [111]

TN (K)

213

230

45 - 55

120

Eg (eV)

1.2

2.137

1.34 (indirect)

2.47 (direct)