Table 1 Typical structural properties of the alkali silicate glasses.

From: Origin of the mixed alkali effect in silicate glass

Glass

SiO2

Na100

Na50K50

K100

Density (g·cm−3)

2.200

2.429

2.439

2.404

Number density (Å−3)

0.06615

0.07280

0.06866

0.06416

NNa-O

4.2

4.1

NNa-BO

2.1

2.0

NNa-NBO

2.1

2.1

NK-O

5.2

4.4

NK-BO

2.9

2.3

NK-NBO

2.3

2.1

Average (Si-O)n ring size

6.6

8.3

7.9

8.1

Fraction of large rings (n13) (%)

0

5.6

7.5

11.0

Cavity volume ratio

32.2

6.6

9.2

13.7

Maximum cavity volume (Å3)

14206

166

323

1310

  1. BO bridging oxygen, NBO non-bridging oxygen, coordination numbers were calculated up to 3.0 Å and 3.3 Å for Na-O and K-O, respectively