Crystal field

Crystal field terms involve either one or \(k\) entities (depending on the mapping procedure choice). Consider case with one entity as a preferred mapping scheme. Then, it can be expressed via the term \(\mathcal{H}_{0, 1}\).

\[\mathcal{H}_{0, 1} = C_{0, 1} \sum_{\mu_1, \alpha_1, i_1} V_{\mu_1; \alpha_1}^{i_1} X_{\mu_1; \alpha_1}^{i_1}\]

The summary of the mapping for each code is given in the table below.

Code

McPhase (v1)

McPhase (v2)

Sunny

\(\mathcal{H}\)

\[\hat{\mathcal{H}} = \sum_n \sum_{lm} B_l^m \hat{O}_{lm}(\mathbf{J}^n)\]
\[\hat{\mathcal{H}} = \sum_n \sum_{lm} L_l^m(n) \hat{T}_{lm}^{n}\]
\[\mathcal{H} = \sum_{i}\sum_{k,q} c_{i,k,q} \mathcal{O}_{k,q} (\mathbf{S}_{i})\]

Indices renaming

\(n \rightarrow (\mu_1, \alpha_1)\), \((l,m) \rightarrow i_1\)

\(n \rightarrow (\mu_1, \alpha_1)\), \((l,m) \rightarrow i_1\)

\(i \rightarrow (\mu_1, \alpha_1)\), \((k,q) \rightarrow i_1\)

\(C_{0, 1}\)

1

1

1

\(V_{\mu_1; \alpha_1}^{i_1}\)

\(B^{i_1}\)

\(L^{i_1}(\mu_1, \alpha_1)\)

\(c_{\mu_1, \alpha_1, i_1}\)

\(X_{\mu_1; \alpha_1}^{i_1}\)

\(\hat{O}_{i_1}(\mathbf{J}^{\mu_1, \alpha_1})\)

\(\hat{T}_{i_1}^{\mu_1, \alpha_1}\)

\(\mathcal{O}_{i_1}(\mathbf{S}_{\mu_1, \alpha_1})\)

Note

  • Pairs of indices \((l,m)\) or \((k,q)\) run over the finite set of the sets of two integers. Therefore, they can be enumerated with a single integer and mapped to the index \(i_1\).