Docs: delay release of deltaspin due to bugs (#4146)

Author: hongriTianqi

docs/advanced/input_files/input-main.md

@@ -370,16 +370,6 @@
     - [tau](#tau)
     - [sigma\_k](#sigma_k)
     - [nc\_k](#nc_k)
-  - [Deltaspin](#deltaspin)
-    - [sc\_mag\_switch](#sc_mag_switch)
-    - [decay\_grad\_switch](#decay_grad_switch)
-    - [sc\_thr](#sc_thr)
-    - [nsc](#nsc)
-    - [nsc\_min](#nsc_min)
-    - [sc\_scf\_nmin](#sc_scf_nmin)
-    - [alpha\_trial](#alpha_trial)
-    - [sccut](#sccut)
-    - [sc\_file](#sc_file)
   - [Quasiatomic Orbital (QO) analysis](#quasiatomic-orbital-qo-analysis)
     - [qo\_switch](#qo_switch)
     - [qo\_basis](#qo_basis)
@@ -3474,128 +3464,6 @@ These variables are used to control the usage of implicit solvation model. This
 
 [back to top](#full-list-of-input-keywords)
 
-## Deltaspin
-
-These variables are used to control the usage of deltaspin functionality.
-
-### sc_mag_switch
-
-- **Type**: boolean
-- **Description**: the switch of deltaspin functionality
-  - 0: no deltaspin
-  - 1: use the deltaspin method to constrain atomic magnetic moments
-- **Default**: 0
-
-### decay_grad_switch
-
-- **Type**: boolean
-- **Description**: the switch of decay gradient method
-  - 0: no decay gradient method
-  - 1: use the decay gradient method and set ScDecayGrad in the file specified by `sc_file`. ScDecayGrad is an element dependent parameter, which is used to control the decay rate of the gradient of the magnetic moment.
-- **Default**: 0
-
-### sc_thr
-
-- **Type**: Real
-- **Description**: the threshold of the spin constraint atomic magnetic moment
-- **Default**: 1e-6
-- **Unit**: Bohr Mag (\muB)
-
-### nsc
-
-- **Type**: Integer
-- **Description**: the maximum number of steps in the inner lambda loop
-- **Default**: 100
-
-### nsc_min
-
-- **Type**: Integer
-- **Description**: the minimum number of steps in the inner lambda loop
-- **Default**: 2
-
-### sc_scf_nmin
-
-- **Type**: Integer
-- **Description**: the minimum number of outer scf loop before initializing lambda loop
-- **Default**: 2
-
-### alpha_trial
-
-- **Type**: Real
-- **Description**: initial trial step size for lambda in eV/uB^2
-- **Default**: 0.01
-- **Unit**: eV/uB^2
-
-### sccut
-
-- **Type**: Real
-- **Description**: restriction of step size in eV/uB
-- **Default**: 3
-- **Unit**: eV/uB
-
-### sc_file
-
-- **Type**: String
-- **Description**: the file in json format to specify atomic constraining parameters. An example of the sc_file json file is shown below for the `nspin 4` case:
-
-```json
-[
-    {
-        "element": "Fe",
-        "itype": 0,
-        "ScDecayGrad": 0.9,
-        "ScAtomData": [
-            {
-                "index": 0,
-                "lambda": [0, 0, 0],
-                "target_mag": [2.0, 0.0, 0.0],
-                "constrain": [1,1,1]
-            },
-            {
-                "index": 1,
-                "lambda": [0, 0, 0],
-                "target_mag_val": 2.0,
-                "target_mag_angle1": 80.0,
-                "target_mag_angle2": 0.0,
-                "constrain": [1,1,1]
-            }
-        ]
-    }
-]
-```
-
-and
-
-```json
-[
-    {
-        "element": "Fe",
-        "itype": 0,
-        "ScDecayGrad": 0.9,
-        "ScAtomData": [
-            {
-                "index": 0,
-                "lambda": 0.0,
-                "target_mag": 2.0,
-                "constrain": 1
-            },
-            {
-                "index": 1,
-                "lambda": 0,
-                "target_mag": 2.0,
-                "constrain": 1
-            }
-        ]
-    }
-]
-```
-
-for `nspin 2` case. The difference is that `lambda`, `target_mag`, and `constrain` are scalars in `nspin 2` case, and are vectors in `nspin 4` case.
-
-- **Default**: none
-
-[back to top](#full-list-of-input-keywords)
-
 ## Quasiatomic Orbital (QO) analysis
 
 These variables are used to control the usage of QO analysis. QO further compress information from LCAO: usually PW basis has dimension in million, LCAO basis has dimension below thousand, and QO basis has dimension below hundred.

docs/advanced/scf/spin.md

@@ -28,47 +28,6 @@ If **"ocp=1"** and **"ocp_set"** is set in INPUT file, the occupations of states
 2. **"nupdown"**
 If **"nupdown"** is set to non-zero, number of spin-up and spin-down electrons will be fixed, and Fermi energy level will split to E_Fermi_up and E_Fermi_down. By the way, total magnetization will also be fixed, and will be the value of **"nupdown"**.
 
-3. DeltaSpin
-The `DeltaSpin` function as proposed by Zefeng Cai and Ben Xu, et al. [arXiv:2208.04551v6](https://arxiv.org/abs/2208.04551) has been implemented in ABACUS in the LCAO basis for the `nspin 2` case. In order to use this function, the following parameters are needed to be set in the input file, for example:
-```
-#deltaspin
-sc_mag_switch                   1
-decay_grad_switch               0
-sc_thr                          1e-7
-nsc                             150
-nsc_min                         2
-sc_file                         sc.json
-alpha_trial                     0.01
-sccut                           3
-```
-The explanation of each input paramters has been explained in the [Noncollinear Spin Polarized Calculations](#noncollinear-spin-polarized-calculations) section.
-
-An example of the sc_file json file is shown below:
-```json
-[
-    {
-        "element": "Fe",
-        "itype": 0,
-        "ScDecayGrad": 0.9,
-        "ScAtomData": [
-            {
-                "index": 0,
-                "lambda": 0.0,
-                "target_mag": 2.0,
-                "constrain": 1
-            },
-            {
-                "index": 1,
-                "lambda": 0,
-                "target_mag": 2.0,
-                "constrain": 1
-            }
-        ]
-    }
-]
-```
-Please refer the [Noncollinear Spin Polarized Calculations](#noncollinear-spin-polarized-calculations) section for the explanation of each input paramters. The difference is that `lambda`, `target_mag`, and `constrain` are scalars instead of vectors. Simple examples are provided in the `abacus-develop/examples/spin_polarized` directory.
-
 ## Noncollinear Spin Polarized Calculations
 The spin non-collinear polarization calculation corresponds to setting **"noncolin 1"**, in which case the coupling between spin up and spin down will be taken into account. 
 In this case, nspin is automatically set to 4, which is usually not required to be specified manually.
@@ -88,54 +47,6 @@ The SOC effect is considered but the magnetic moment is limited to the Z directi
  - noncolin=1 lspinorb=1 : 
 The SOC effect and non-collinear magnetic moment are both calculated.
 
-### Constraint Spin functionality for noncollinear spin polarized calculations
-
-The `DeltaSpin` function as proposed by Zefeng Cai and Ben Xu, et al. [arXiv:2208.04551v6](https://arxiv.org/abs/2208.04551) has been implemented in ABACUS in the LCAO basis. In order to use this function, the following parameters are needed to be set in the input file, for example:
-```
-#deltaspin
-sc_mag_switch                   1
-decay_grad_switch               1
-sc_thr                          1e-7
-nsc                             150
-nsc_min                         2
-sc_file                         sc.json
-alpha_trial                     0.01
-sccut                           3
-```
-
-
-`sc_mag_switch` is the switch of deltaspin functionality; `decay_grad_switch` is the switch of decay gradient method; `sc_thr` is the threshold of the spin constraint atomic magnetic moment in unit of Bohr Mag (\muB); `nsc` is the number of self-consistent iterations; `nsc_min` is the minimum number of self-consistent iterations; `sc_file` is the file name of the spin constraint parameters; `alpha_trial` is the initial trial step size for lambda in eV/uB^2; `sccut` restriction of step size in eV/uB.
-
-An example of the sc_file json file is shown below:
-```json
-[
-    {
-        "element": "Fe",
-        "itype": 0,
-        "ScDecayGrad": 0.9,
-        "ScAtomData": [
-            {
-                "index": 0,
-                "lambda": [0, 0, 0],
-                "target_mag": [2.0, 0.0, 0.0],
-                "constrain": [1,1,1]
-            },
-            {
-                "index": 1,
-                "lambda": [0, 0, 0],
-                "target_mag_val": 2.0,
-                "target_mag_angle1": 80.0,
-                "target_mag_angle2": 0.0,
-                "constrain": [1,1,1]
-            }
-        ]
-    }
-]
-```
-
-The sc_file json file is a list of elemental data in total. For each element, the user should specify its name, the `itype` parameter should be in accord with `STRU` file and start from 0. `ScDecayGrad` is a parameter for each element in unit of  (uB^2/eV), this parameter needs to be determined for different element, for example, 0.9 uB^2/eV is an appropriate value for BCC-Fe according to Zefeng Cai's tests. `ScAtomData` specifies spin constraining parameters for each atom, the `index` starts from 0 and corresponds atomic order in the `STRU` file. `lambda` is a 3d vector for each atom, and it is recommended to set to [0.0, 0.0, 0.0] for all atoms. Users have two optional choices to set the target magnetic moments for each atom, i.e., by a 3d vector or by angles. If the `target_mag` is set, the `target_mag_val` and `target_mag_angle1` and `target_mag_angle2` will be ignored. The `target_mag` is a 3d vector in unit of Bohr Mag (\muB), and the `target_mag_val` is a scalar value in unit of Bohr Mag (\muB), `target_mag_angle1` and `target_mag_angle2` are two angles in unit of degree. The `constrain` is a 3d vector, if the corresponding element is set to 1, the corresponding component of the magnetic moment will be constrained, otherwise, it will be free. Note that the initial atomic magnetic moments are still set in the `STRU` file. Simple examples are provided in the `abacus-develop/examples/noncollinear` directory. One should set `noncolliear` to 1 to run the DeltaSpin function, `lspinorb=1` is not mandatory, but it is recommended to set to 1 to get more accurate results.
-
-
 ## For the continuation job
 - Continuation job for "nspin 1" need file "SPIN1_CHG.cube" which is generated by setting "out_chg=1" in task before. By setting "init_chg file" in new job's INPUT file, charge density will start from file but not atomic. 
 - Continuation job for "nspin 2" need files "SPIN1_CHG.cube" and "SPIN2_CHG.cube" which are generated by "out_chg 1" with "nspin 2", and refer to spin-up and spin-down charge densities respectively. It should be note that reading "SPIN1_CHG.cube" only for the continuation target magnetic moment job is not supported now.