是指同晶体结构的原子形成的固溶体的点阵常数是两者点阵常数的一个中间值.用Ag和Cu的原子坐标可以写成a=x1a1+x2a2

x1,x2,a1,a2分别指两种单质的百分含量和点阵常数.

一般写成:a=x1a1+(1-x1)a2

因为X1+X2=1,有时把X写成C

In metallurgy, Vegard's law is an approximate empirical rule which holds that a linear relation exists, at constant temperature, between the crystal lattice parameter of an alloy and the concentrations of the constituent elements.

For example, consider the semiconductor compound InPxAs1-x. A relation exists between the constituent elements and their associated lattice parameters, a, such that:

aInPAs = xaInP + (1 − x)aInAs

One can also extend this relation to determine semiconductor band gap energies. Using InPxAs1-x as before one can find an expression that relates the band gap energies, Eg, to the ratio of the constituents and a bowing parameter b: