|  | ###### Perform SOC calculations {#perform_soc_calculations} |  | # Perform SOC calculations | 
|  |  |  |  | 
|  | To include spin-orbit coupling (SOC) into the system of study we take |  | To include spin-orbit coupling (SOC) into the system of study we take | 
|  | the scalar-relativistic Hamiltonian and add SOC in the Pauli-form \$ |  | the scalar-relativistic Hamiltonian and add SOC in the Pauli-form $`\mathcal{H}_\mathrm{SO} = \xi \, L \cdot S`$. This is done by the | 
|  | \\mathcal{H}\_\\mathrm{SO} = \\xi \\, L \\cdot S\$. This is done by the |  | new solver. **Note that the new solver works only for spin-polarized | 
|  | new solver. \_\_Note that the new solver works only for spin-polarized |  | full potential calculations.** The features of the old solver like for | 
|  | full potential calculations.\_\_ The features of the old solver like for |  | example [DOS](jumu/density_of_states), | 
|  | example [DOS](jumu/density_of_states "wikilink"), |  | [QDOS](jumu/qdos), or [decimation](jumu/deci) work | 
|  | [QDOS](jumu/qdos "wikilink"), or [decimation](jumu/deci "wikilink") work |  |  | 
|  | as usual. The following steps are needed: |  | as usual. The following steps are needed: | 
|  |  |  |  | 
|  | ##### Changes in the inputcard {#changes_in_the_inputcard} |  | ## Changes in the inputcard | 
|  |  |  |  | 
|  | The options //NEWSOSOL// and //fullBZ// have to be set in the inputcard. |  | The options *NEWSOSOL* and *fullBZ* have to be set in the inputcard. | 
|  | This tells the program to use the new solver and to forget about all |  | This tells the program to use the new solver and to forget about all | 
|  | symmetries previously found for the current setup. This is needed since |  | symmetries previously found for the current setup. This is needed since | 
|  | SOC may break some symmetries. In addition some parameters for the |  | SOC may break some symmetries. In addition some parameters for the | 
|  | newsolver have to be set. These are //NPAN\_LOG//, //NPAN\_EQ//, |  | newsolver have to be set. These are *NPAN_LOG*, *NPAN_EQ*, | 
|  | //NCHEB// and //R\_LOG//. Also do not forget to do spin-polarized |  | *NCHEB* and *R_LOG*. Also do not forget to do spin-polarized | 
|  | calculations for full potential (//NSPIN=2, KSHAPE=2//). If you started |  | calculations for full potential (*NSPIN=2, KSHAPE=2*). If you started | 
|  | with a calculation without spin-polarization, i.e. *NSPIN=1*, you can |  | with a calculation without spin-polarization, i.e. *NSPIN=1*, you can | 
|  | [adopt your already converged |  | [adopt your already converged potential](change_nspin_1_to_2). | 
|  | potential](change_nspin_1_to_2 "wikilink"). <code> RUNOPT NEWSOSOL \... |  | ``` | 
|  | \... |  | RUNOPT | 
|  | +\-\-\-\-\-\--+\-\-\-\-\-\--+\-\-\-\-\-\--+\-\-\-\-\-\--+\-\-\-\-\-\--+ |  | NEWSOSOL ...     ... | 
|  |  |  | +-------+-------+-------+-------+-------+ | 
|  |  |  |  | 
|  | `     ***test options*** (2 lines) ` |  | `     ***test options*** (2 lines) ` | 
|  |  |  |  | 
|  | TESTOPT fullBZ |  | TESTOPT fullBZ | 
|  | +\-\-\-\-\-\--+\-\-\-\-\-\--+\-\-\-\-\-\--+\-\-\-\-\-\--+\-\-\-\-\-\--+ |  | +-------+-------+-------+-------+-------+ | 
|  |  |  |  | 
|  | \... |  | ... | 
|  |  |  |  | 
|  | NSPIN=2 |  | NSPIN=2 | 
|  |  |  |  | 
|  | \... |  | ... | 
|  |  |  |  | 
|  | KSHAPE=2 |  | KSHAPE=2 | 
|  |  |  |  | 
|  | \... |  | ... | 
|  |  |  |  | 
|  | HFIELD= 0.0 VCONST= 0.0d0 NPAN\_LOG= 15 NPAN\_EQ= 5 NCHEB= 12 R\_LOG= |  | HFIELD= 0.0 VCONST= 0.0d0 NPAN_LOG= 15 NPAN_EQ= 5 NCHEB= 12 R_LOG= | 
|  | 1.0d0 |  | 1.0d0 | 
|  |  |  |  | 
|  | BZDIVIDE= 30 30 30 |  | BZDIVIDE= 30 30 30 | 
|  |  |  |  | 
|  | \... </code> If the new solver without SOC should be used the test |  | ... | 
|  | option //NOSOC// has to be added. |  | ``` | 
|  |  |  | If the new solver without SOC should be used the test | 
|  |  |  | option *NOSOC* has to be added. | 
|  |  |  |  | 
|  | ##### additional input files {#additional_input_files} |  | ## additional input files | 
|  |  |  |  | 
|  | Since the new solver does also deal with non-collinear calculations we |  | Since the new solver does also deal with non-collinear calculations we | 
|  | have to specify the non-collinear angles of each atom in the inputcard |  | have to specify the non-collinear angles of each atom in the inputcard | 
|  | in the file [nonco\_angle.dat](jumu/nonco_angle.dat_file "wikilink"). If |  | in the file [nonco_angle.dat](jumu/nonco_angle.dat_file). If | 
|  | this file is not given then the angles are fixed to theta=phi=0 (i.e. |  | this file is not given then the angles are fixed to theta=phi=0 (i.e. | 
|  | the z-direction). |  | the z-direction). | 
|  |  |  |  | 
|  | ##### Examples |  | ## Examples | 
|  |  |  |  | 
|  | #### Example 1: bulk Au with and without SOC {#example_1_bulk_au_with_and_without_soc} |  | ### Example 1: bulk Au with and without SOC | 
|  |  |  |  | 
|  | As an example the difference between bulk Au with and without SOC should |  | As an example the difference between bulk Au with and without SOC should | 
|  | be calculated. The test system consists of bulk Au (fcc lattice) with a |  | be calculated. The test system consists of bulk Au (fcc lattice) with a | 
| ... | @@ -65,14 +67,15 @@ LMAX cutoff set to 2 and a k-mesh of 15x15x15, for the sake of speed of | ... | @@ -65,14 +67,15 @@ LMAX cutoff set to 2 and a k-mesh of 15x15x15, for the sake of speed of | 
|  | the calculation. |  | the calculation. | 
|  | `{{:jumu/examples:au_bulk_nosoc_cos.tar.gz|Here}}`{=mediawiki} the input |  | `{{:jumu/examples:au_bulk_nosoc_cos.tar.gz|Here}}`{=mediawiki} the input | 
|  | files of both cases with the different inputcards can be found. Using |  | files of both cases with the different inputcards can be found. Using | 
|  | the [QDOS](jumu/qdos "wikilink") the change in the band structure can be |  | the [QDOS](jumu/qdos) the change in the band structure can be | 
|  | investigated. |  | investigated. | 
|  |  |  |  | 
|  | #### Example 2: bulk Au with and without SOC {#example_2_bulk_au_with_and_without_soc} |  | ### Example 2: bulk Au with and without SOC | 
|  |  |  |  | 
|  | The second example is the SOC-induced splitting of Au(111) surface |  | The second example is the SOC-induced splitting of Au(111) surface | 
|  | states using a half-infinite Au(111) crystal (using the |  | states using a half-infinite Au(111) crystal (using the | 
|  | [decimation-technique](jumu/deci "wikilink")) and the |  | [decimation-technique](jumu/deci)) and the | 
|  | [QDOS](jumu/qdos "wikilink") option. \<WRAP center round todo 60%\> Add |  | [QDOS](jumu/qdos) option. | 
|  | example files with instructions, also to [examples |  |  | 
|  | page](jumu/examples_and_tips "wikilink"). </WRAP> |  | ## TODO | 
|  |  |  | Addexample files with instructions, also to [examples page](jumu/examples_and_tips). |