Five undetermined parameters are determined by experimental data of the total energy, three second order elastic constants and the lattice constant of the crystal at o K and zero pressure.

五个待定参数用零温零压下晶体的总能、三个二阶弹性常数以及晶格常数的实验值确定。

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In general, special solution of non-homogeneous linear equation of constant coefficient of the second order is obtained by the method of undetermined coefficient, but it's process is too complicated.

二阶常系数非齐次线性微分方程的特解一般都是用“待定系数”法求得的，但求解过程都比较繁琐。

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