Exchange striction¶
Exchange striction involves two entities of type \(X\) and one entity of type \(Y\). Therefore, it can be expressed via the term \(\mathcal{H}_{1, 2}\).
\[\begin{split}\mathcal{H}_{1, 2}
=
C_{1, 2}
\sum_{\substack{\mu_1, \mu_2,\\ \alpha_1, \alpha_2,\\ j_1, i_1, i_2}}
V_{1; \mu_1, \mu_2; \alpha_1, \alpha_2}^{j_1, i_1, i_2}
Y_{1}^{j_1}
X_{\mu_1; \alpha_1}^{i_1}
X_{\mu_2; \alpha_2}^{i_2}\end{split}\]
The summary of the mapping for each code is given in the table below.
Code |
|
|---|---|
\(\mathcal{H}\) |
\[\begin{split}\hat{\mathcal{H}}
=
-
\dfrac{1}{2}
\sum_{\substack{nn^{\prime},\alpha\beta\alpha^{\prime}\gamma=1,2,3\\\beta^{\prime}=1-6}}
\Biggl(
\dfrac{\partial \mathcal{J}_{\alpha\beta}}{\partial \epsilon_{\beta^{\prime}}}
+
\dfrac{\partial \mathcal{J}_{\alpha\beta}}{\partial R_{nn^{\prime}}^{\alpha^{\prime}}}
\dfrac{\partial \epsilon_{\alpha^{\prime}\gamma} R_{nn^{\prime}}^{\gamma}}{\partial \epsilon_{\beta^{\prime}}}
\Biggr)
\epsilon_{\beta^{\prime}}
\hat{\mathcal{I}}_{\alpha}^n
\hat{\mathcal{I}}_{\beta}^{n^{\prime}}\end{split}\]
|
Indices renaming |
\(n \rightarrow (\mu_1, \alpha_1)\), \(n^{\prime} \rightarrow (\mu_2, \alpha_2)\), \(\alpha \rightarrow i_1\), \(\beta \rightarrow i_2\) \(\beta^{\prime} \rightarrow j_1\) |
\(C_{1, 2}\) |
\(-\dfrac{1}{2}\) |
\(V_{1; \mu_1, \mu_2; \alpha_1, \alpha_2}^{j_1, i_1, i_2}\) |
\[\sum_{\alpha^{\prime}\gamma=1,2,3}
\Biggl(
\dfrac{\partial \mathcal{J}_{i_1,i_2}}{\partial \epsilon_{j_1}}
+
\dfrac{\partial \mathcal{J}_{i_1,i_2}}{\partial R_{\mu_1,\mu_2;\alpha_1,\alpha_2}^{\alpha^{\prime}}}
\dfrac{\partial \epsilon_{\alpha^{\prime}\gamma} R_{\mu_1,\mu_2;\alpha_1,\alpha_2}^{\gamma}}{\partial \epsilon_{j_1}}
\Biggr)\]
|
\(Y_{1}^{j_1}\) |
\(\epsilon_{j_1}\) |
\(X_{\mu_1; \alpha_1}^{i_1}\) |
\(\hat{\mathcal{I}}_{i_1}^{\mu_1,\alpha_1}\) |
\(X_{\mu_2; \alpha_2}^{i_2}\) |
\(\hat{\mathcal{I}}_{i_2}^{\mu_2,\alpha_2}\) |