Differences
This shows you the differences between two versions of the page.
| Next revision | Previous revision | ||
| forum:data:2024:unexpected_mixed_singlet_and_triplet_states [2024/12/04 23:29] – Created from the form at forum:start Charles Cardot | forum:data:2024:unexpected_mixed_singlet_and_triplet_states [2024/12/04 23:34] (current) – Maurits W. Haverkort | ||
|---|---|---|---|
| Line 9: | Line 9: | ||
| I was exploring how the Coulomb exchange coupling between different orbitals gives rise to states with different multiplicities. In this simplest non-trivial case (two unpaired electrons, one in each orbital) this should give rise to triplet and singlet states, where the triplet states have a <S^2> = 2 (s=1) and the singlet states have <S^2> = 0 (s=0). The code I used is shown below. | I was exploring how the Coulomb exchange coupling between different orbitals gives rise to states with different multiplicities. In this simplest non-trivial case (two unpaired electrons, one in each orbital) this should give rise to triplet and singlet states, where the triplet states have a <S^2> = 2 (s=1) and the singlet states have <S^2> = 0 (s=0). The code I used is shown below. | ||
| + | < | ||
| -- Create Index | -- Create Index | ||
| Index, NFermi = CreateAtomicIndicesDict({" | Index, NFermi = CreateAtomicIndicesDict({" | ||
| Line 163: | Line 164: | ||
| print(" | print(" | ||
| + | </ | ||
| Running this code produces the following output: | Running this code produces the following output: | ||
| + | < | ||
| ============================================================= | ============================================================= | ||
| ==== written by Maurits W. Haverkort, | ==== written by Maurits W. Haverkort, | ||
| Line 330: | Line 331: | ||
| Finished | Finished | ||
| + | </ | ||
| The Hamiltonian setup is a system with only a single *d* electron, and one hole in either the *s* or *p* level. When there is a hole in the *s* orbital there are 20 eigenstate (2x10) with 15 of them being triplet states and 5 of them being singlet states at a slightly different energy (G2sd = 0.05 eV). This is the expected behavior. | The Hamiltonian setup is a system with only a single *d* electron, and one hole in either the *s* or *p* level. When there is a hole in the *s* orbital there are 20 eigenstate (2x10) with 15 of them being triplet states and 5 of them being singlet states at a slightly different energy (G2sd = 0.05 eV). This is the expected behavior. | ||
