Table 2. Parameters Related to the Basic Physical Properties of the Different Glasses along with Cation Radii, r, Based on Shannon¹⁴ for Eightfold-Coordinated Ba²⁺ Ions²⁴ and Sixfold-Coordinated Ln³⁺ Ions,^25,26 and the Corresponding Calculated Field Strengths.

parameter	glass
	Ba	Nd	Gd	Yb
density, ρ (g/cm3)	3.700	3.780	3.826	3.794
average molar mass, Mav (g/mol)	147.64	154.96	156.00	157.27
molar volume, Vm (cm3/mol)	39.90	40.99	40.77	41.45
Ln3+ concentration, N (× 1020 ions/cm3)		11.75	11.82	11.62
Ln3+–Ln3+ mean distance, d (Å)		9.48	9.46	9.51
[O]/[P]	3.00	3.08	3.08	3.08
cation radius,ar (Å)	1.42	0.983	0.938	0.868
cation field strength, F = Z/r2 (Å–2)	0.992	3.105	3.410	3.982

^aFrom Shannon.¹⁴