Ways to assign basis sets
#########################

Similar to the other part of the input file in BAGH, the basis set assignment is case and space-insensitive (as long as different keywords are separated) unless mentioned otherwise. There are 3 ways basis sets are assigned to different atoms in BAGH (arranged according to the priorities):

1. Atom-specific basis set
2. Custom basis set
3. Universal basis set

The highest priority is given to the atom-specific basis sets, and the lowest goes to the universal basis set assignment. If no basis set is assigned to an atom at all, by default, STO-3G is assigned to it.

A sample input file is shown below:

Example 1:

.. code-block:: shell 

   ! CCSD pos3   pos4   pos5

   %cc
   incore 5
   end

   %basis
   pos2
   end

   *xyz 0 1
   H	 0.0000	-0.9377	-0.3816   pos1
   H	 0.8121	 0.4689	-0.3816
   H	-0.8121	 0.4689	-0.3816
   N	 0.0000	 0.0000	 0.0000    

All 3 positions are shown in the above example. ``pos1``, ``pos2`` and ``pos3`` refer to the positions of atom-specific basis, custom basis and universal basis, respectively. A basis set can be assigned to an atom in either of these 3 ways. In the above example, one of the ``H`` atoms is being assigned a basis set from the atom-specific basis (``pos1``). The rest of the two ``H`` atoms and the ``N`` atom can either be assigned by the custom basis (``pos2``) or the universal basis (``pos3``) only if any atom is left unassigned in the custom basis. Let's say custom basis only contains basis functions for ``N`` atom, then rest of the two ``H`` atoms will be assigned from the universal basis in ``pos3``. The positions ``pos4`` and ``pos5`` refer to the position of JK and RI basis positions, respectively (if any).

.. note::

      - One can assign a JK auxiliary basis even if there is no universal main basis.
      - One can assign a RI auxiliary basis even if there is no universal main basis or JK auxiliary basis or both.
      - JK and  RI auxiliary basis sets are only assigned in the RHF (spin-summed MO) interface of the code.

***********************
Atom-specific basis set
***********************

Atom-specific basis sets are written within the coordinate block ``*xyz`` in the 5th column as in ``pos1`` in Example 1. The basis set is assigned only to that particular atom (eg. first ``H`` atom in Example 1). The rest of the atoms remain unassigned. A sample input file is shown where all of the atoms are assigned using atom-specific basis set.

Example 2:

.. code-block:: shell 

   ! CCSD spinor

   %cc
   incore 5
   end

   *xyz 0 1
   H	 0.0000	-0.9377	-0.3816   ccpvdz
   H	 0.8121	 0.4689	-0.3816   ccpvdz
   H	-0.8121	 0.4689	-0.3816   ccpvdz
   N	 0.0000	 0.0000	 0.0000   augccpvdz

Here all 3 ``H`` atoms are assigned ``cc-pVDZ`` basis set, while ``N`` atom is assigned to ``aug-cc-pVDZ`` basis set. One can also assign different basis sets for different atoms of the same element as in the following example.

Example 3:

.. code-block:: shell 

   ! CCSD spinor

   %cc
   incore 5
   end

   *xyz 0 1
   H	 0.0000	-0.9377	-0.3816   ccpvdz
   H	 0.8121	 0.4689	-0.3816   631g
   H	-0.8121	 0.4689	-0.3816   ccpvtz
   N	 0.0000	 0.0000	 0.0000   augccpvdz


****************
Custom basis set
****************

If an atom remains unassigned to any basis set in an atom-specific way, the flow of code searches for that atom in the custom basis set. The custom basis set is provided within ``%basis`` block of the input file and it ends with a single ``end`` at the end. There should not be any other text in the middle as they may interfere with the proper running of the code, especially another ``end`` in the middle. Only one ``end`` keyword will be used for the entire ``%basis`` block. The custom basis has to be in the ``NWCHEM`` format.

.. caution::

   **Space-sensitivity in the custom basis:** Basis function type eg. ``S``, ``P``, ``D``, ``F``... has to start from the 6th column of the input file.

A sample input file is provided containing only custom basis assignment to each atom.

Example 4:

.. code-block:: shell 

   ! CCSD spinor

   %cc
   incore 5
   end

   %basis
   H    S
         1.301000E+01           1.968500E-02           0.000000E+00
         1.962000E+00           1.379770E-01           0.000000E+00
         4.446000E-01           4.781480E-01           0.000000E+00
         1.220000E-01           5.012400E-01           1.000000E+00
   H    P
         7.270000E-01           1.0000000
   N    S
         9.046000E+03           7.000000E-04          -1.530000E-04           0.000000E+00
         1.357000E+03           5.389000E-03          -1.208000E-03           0.000000E+00
         3.093000E+02           2.740600E-02          -5.992000E-03           0.000000E+00
         8.773000E+01           1.032070E-01          -2.454400E-02           0.000000E+00
         2.856000E+01           2.787230E-01          -6.745900E-02           0.000000E+00
         1.021000E+01           4.485400E-01          -1.580780E-01           0.000000E+00
         3.838000E+00           2.782380E-01          -1.218310E-01           0.000000E+00
         7.466000E-01           1.544000E-02           5.490030E-01           0.000000E+00
         2.248000E-01          -2.864000E-03           5.788150E-01           1.000000E+00
   N    P
         1.355000E+01           3.991900E-02           0.000000E+00
         2.917000E+00           2.171690E-01           0.000000E+00
         7.973000E-01           5.103190E-01           0.000000E+00
         2.185000E-01           4.622140E-01           1.000000E+00
   N    D
         8.170000E-01           1.0000000
   end

   *xyz 0 1
   H	 0.0000	-0.9377	-0.3816
   H	 0.8121	 0.4689	-0.3816
   H	-0.8121	 0.4689	-0.3816
   N	 0.0000	 0.0000	 0.0000

If one wants to assign different basis sets to different atoms of the same element, eg. ``aug-cc-pVDZ`` basis set need to be assigned to one of the ``H`` atom and for all other atoms ``cc-pVDZ`` need to be assigned, one can do that using custom basis but in that case one has to number the atoms (Here ``H`` atoms).

Example 5:

.. code-block:: shell 

   ! CCSD spinor

   %cc
   incore 5
   end

   %basis
   H    S
         1.301000E+01           1.968500E-02           0.000000E+00
         1.962000E+00           1.379770E-01           0.000000E+00
         4.446000E-01           4.781480E-01           0.000000E+00
         1.220000E-01           5.012400E-01           1.000000E+00
   H    P
         7.270000E-01           1.0000000
   H1   S
         1.301000E+01           1.968500E-02           0.000000E+00
         1.962000E+00           1.379770E-01           0.000000E+00
         4.446000E-01           4.781480E-01           0.000000E+00
         1.220000E-01           5.012400E-01           1.000000E+00
   H1   S
         0.0297400              1.0000000
   H1   P
         7.270000E-01           1.0000000
   H1   P
         0.1410000              1.0000000 
   N    S
         9.046000E+03           7.000000E-04          -1.530000E-04           0.000000E+00
         1.357000E+03           5.389000E-03          -1.208000E-03           0.000000E+00
         3.093000E+02           2.740600E-02          -5.992000E-03           0.000000E+00
         8.773000E+01           1.032070E-01          -2.454400E-02           0.000000E+00
         2.856000E+01           2.787230E-01          -6.745900E-02           0.000000E+00
         1.021000E+01           4.485400E-01          -1.580780E-01           0.000000E+00
         3.838000E+00           2.782380E-01          -1.218310E-01           0.000000E+00
         7.466000E-01           1.544000E-02           5.490030E-01           0.000000E+00
         2.248000E-01          -2.864000E-03           5.788150E-01           1.000000E+00
   N    P
         1.355000E+01           3.991900E-02           0.000000E+00
         2.917000E+00           2.171690E-01           0.000000E+00
         7.973000E-01           5.103190E-01           0.000000E+00
         2.185000E-01           4.622140E-01           1.000000E+00
   N    D
         8.170000E-01           1.0000000
   end

   *xyz 0 1
   H	 0.0000	-0.9377	-0.3816
   H	 0.8121	 0.4689	-0.3816
   H	-0.8121	 0.4689	-0.3816
   N	 0.0000	 0.0000	 0.0000

In the above example, ``H1`` (first hydrogen atom) is assigned to the custom basis set of ``aug-cc-pVDZ``, while all other ``H`` atoms and ``N`` are assigned to ``cc-pVDZ`` basis set. In the ``%basis`` block, only the element (eg. ``H`` here) written in the left side (the place of atom) assigns it to all unassigned atoms of the same element. The numbered atom (eg. ``H1`` in this case) takes the priority to be assigned differently.

.. note::
   Numbered atoms are prioritized over unnumbered atoms in the ``%basis`` block.

.. caution::
      - Numbered atoms' basis sets have to be written after the basis set for the unnumbered atom (if any) of the same elemnt in the ``%basis`` block.
      - If numbered atoms are present in the custom basis set, a warning pops up saying *"Custom basis provided for specified elements will be overwritten."*. That can be ignored in such cases.
   

*******************
Universal basis set
*******************

If no basis set is assigned to an atom, it gets assigned using the universal basis set as in ``pos3`` in Example 1. Universal basis set is a single basis set that gets assigned to all atoms yet unassigned. Let's see an example:

Example 6:

.. code-block:: shell 

   ! CCSD spinor ccpvdz

   %cc
   incore 5
   end

   *xyz 0 1
   H	 0.0000	-0.9377	-0.3816
   H	 0.8121	 0.4689	-0.3816
   H	-0.8121	 0.4689	-0.3816
   N	 0.0000	 0.0000	 0.0000

Here, in Example 6, all atoms are assigned to ``cc-pVDZ`` basis set.

Now, let's discuss a complicated basis assignment (see following):

Example 7:

.. code-block:: shell 

   ! CCSD spinor def2qzvp

   %cc
   incore 5
   end

   %basis
   H    S
         1.301000E+01           1.968500E-02           0.000000E+00
         1.962000E+00           1.379770E-01           0.000000E+00
         4.446000E-01           4.781480E-01           0.000000E+00
         1.220000E-01           5.012400E-01           1.000000E+00
   H    P
         7.270000E-01           1.0000000
   H1   S
         1.301000E+01           1.968500E-02           0.000000E+00
         1.962000E+00           1.379770E-01           0.000000E+00
         4.446000E-01           4.781480E-01           0.000000E+00
         1.220000E-01           5.012400E-01           1.000000E+00
   H1   S
         0.0297400              1.0000000
   H1   P
         7.270000E-01           1.0000000
   H1   P
         0.1410000              1.0000000 
   end

   *xyz 0 1
   H	 0.0000	-0.9377	-0.3816
   H	 0.8121	 0.4689	-0.3816
   H	-0.8121	 0.4689	-0.3816   631g
   N	 0.0000	 0.0000	 0.0000

Here, ``H1`` is assigned to the custom basis of ``aug-cc-pVDZ`` as a numbered atom, ``H2`` is assigned to the custom basis of ``cc-pVDZ`` as an unnumbered atom, ``H3`` is assigned to ``6-31G`` basis set as atom-specific assignment and ``N`` atom is assigned to the ``def2-QZVP`` basis set as an universal basis set of this input file.

If an atom still remains unassigned (as follows), it by default, gets assigned to ``STO-3G`` basis set.

Example 8:

.. code-block:: shell 

   ! CCSD spinor

   %cc
   incore 5
   end

   %basis
   H    S
         1.301000E+01           1.968500E-02           0.000000E+00
         1.962000E+00           1.379770E-01           0.000000E+00
         4.446000E-01           4.781480E-01           0.000000E+00
         1.220000E-01           5.012400E-01           1.000000E+00
   H    P
         7.270000E-01           1.0000000
   H1   S
         1.301000E+01           1.968500E-02           0.000000E+00
         1.962000E+00           1.379770E-01           0.000000E+00
         4.446000E-01           4.781480E-01           0.000000E+00
         1.220000E-01           5.012400E-01           1.000000E+00
   H1   S
         0.0297400              1.0000000
   H1   P
         7.270000E-01           1.0000000
   H1   P
         0.1410000              1.0000000 
   end

   *xyz 0 1
   H	 0.0000	-0.9377	-0.3816
   H	 0.8121	 0.4689	-0.3816
   H	-0.8121	 0.4689	-0.3816   631g
   N	 0.0000	 0.0000	 0.0000

Here, in Example 8, ``N`` atom is not assigned to any basis in any way. So, it takes ``STO-3G`` basis set.

Basis set assignment to ghost atoms
###################################

Ghost atoms are defined as ``X`` atom in BAGH. Basis sets to ghost atoms are assigned in the same way as other atoms. In the Example 8, if first two ``H`` atoms are replaced by ghost atoms, the input structure looks like the following.

Example 9:

.. code-block:: shell 

   ! CCSD spinor

   %cc
   incore 5
   end

   %basis
   X    S
         1.301000E+01           1.968500E-02           0.000000E+00
         1.962000E+00           1.379770E-01           0.000000E+00
         4.446000E-01           4.781480E-01           0.000000E+00
         1.220000E-01           5.012400E-01           1.000000E+00
   X    P
         7.270000E-01           1.0000000
   X1   S
         1.301000E+01           1.968500E-02           0.000000E+00
         1.962000E+00           1.379770E-01           0.000000E+00
         4.446000E-01           4.781480E-01           0.000000E+00
         1.220000E-01           5.012400E-01           1.000000E+00
   X1   S
         0.0297400              1.0000000
   X1   P
         7.270000E-01           1.0000000
   X1   P
         0.1410000              1.0000000 
   end

   *xyz 0 1
   X	 0.0000	-0.9377	-0.3816
   X	 0.8121	 0.4689	-0.3816
   H	-0.8121	 0.4689	-0.3816   631g
   N	 0.0000	 0.0000	 0.0000

Basis set assignments in BAGH can be checked from the ouput file whether they are assigned correctly.

Available basis sets
####################

**************
Main basis set
**************

There are several basis sets that are currently available in BAGH as a keyword. Basis sets keywords are usually slightly different than their respective names but they are simple and comprehensible eg. ``aug-cc-pVDZ`` basis set is called as ``augccpvdz`` etc. Following is the list of exact keywords of all currently available basis sets in BAGH.

.. raw:: html

   <!-- Dropdown Menu HTML -->
   <div class="dropdown">
       <button class="dropdown-btn">Choose main basis</button>
       <div class="dropdown-content" style="display: none;">
           <ul>
               <li>ano</li>
               <li>anorcc</li>
               <li>anoroosdz</li>
               <li>anoroostz</li>
               <li>roosdz</li>
               <li>roostz</li>
               <li>ccpvdz</li>
               <li>ccpvtz</li>
               <li>ccpvqz</li>
               <li>ccpv5z</li>
               <li>augccpvdz</li>
               <li>augccpvtz</li>
               <li>augccpvqz</li>
               <li>augccpv5z</li>
               <li>ccpvdzdk</li>
               <li>ccpvtzdk</li>
               <li>ccpvqzdk</li>
               <li>ccpv5zdk</li>
               <li>ccpvdzdkh</li>
               <li>ccpvtzdkh</li>
               <li>ccpvqzdkh</li>
               <li>ccpv5zdkh</li>
               <li>augccpvdzdk</li>
               <li>augccpvtzdk</li>
               <li>augccpvqzdk</li>
               <li>augccpv5zdk</li>
               <li>augccpvdzdkh</li>
               <li>augccpvtzdkh</li>
               <li>augccpvqzdkh</li>                                                                                  
               <li>augccpv5zdkh</li>                                                  
               <li>ccpvdzri</li>                                                                                  
               <li>ccpvtzri</li>                                                                                
               <li>ccpvqzri</li>                                                                                      
               <li>ccpv5zri</li>                                                                                      
               <li>augccpvdzri</li>
               <li>augccpvdzpri</li>
               <li>augccpvqzri</li>
               <li>augccpvtzri</li>
               <li>ccpvtzdk3</li>
               <li>ccpvqzdk3</li>
               <li>augccpvtzdk3</li>
               <li>augccpvqzdk3</li>
               <li>dyalldz</li>
               <li>dyalltz</li>
               <li>dyallqz</li>
               <li>faegredz</li>
               <li>iglo</li>
               <li>iglo3</li>
               <li>321++g</li>
               <li>321++g*</li>
               <li>321++gs</li>
               <li>321g</li>
               <li>321g*</li>
               <li>321gs</li>
               <li>431g</li>
               <li>631++g</li>
               <li>631++g*</li>
               <li>631++gs</li>
               <li>631++g**</li>
               <li>631++gss</li>
               <li>631+g</li>
               <li>631+g*</li>
               <li>631+gs</li>
               <li>631+g**</li>
               <li>631+gss</li>
               <li>6311++g</li>
               <li>6311++g*</li>
               <li>6311++gs</li>
               <li>6311++g**</li>
               <li>6311++gss</li>
               <li>6311+g</li>
               <li>6311+g*</li>
               <li>6311+gs</li>
               <li>6311+g**</li>
               <li>6311+gss</li>
               <li>6311g</li>
               <li>6311g*</li>
               <li>6311gs</li>
               <li>6311g**</li>
               <li>6311gss</li>
               <li>631g</li>
               <li>631g*</li>
               <li>631gs</li>
               <li>631g**</li>
               <li>631gss</li>
               <li>sto3g</li>
               <li>sto6g</li>
               <li>minao</li>
               <li>dz</li>
               <li>dzpdunning</li>
               <li>dzvp</li>
               <li>dzvp2</li>
               <li>dzp</li>
               <li>tzp</li>
               <li>qzp</li>
               <li>adzp</li>
               <li>atzp</li>
               <li>aqzp</li>
               <li>dzpdk</li>
               <li>tzpdk</li>
               <li>qzpdk</li>
               <li>dzpdkh</li>
               <li>tzpdkh</li>
               <li>qzpdkh</li>
               <li>def2svp</li>
               <li>def2svpd</li>
               <li>def2tzvpd</li>
               <li>def2tzvppd</li>
               <li>def2tzvpp</li>
               <li>def2tzvp</li>
               <li>def2qzvpd</li>
               <li>def2qzvppd</li>
               <li>def2qzvpp</li>
               <li>def2qzvp</li>
               <li>def2svpri</li>
               <li>def2svpdri</li>
               <li>def2tzvpri</li>
               <li>def2tzvpdri</li>
               <li>def2tzvppri</li>
               <li>def2tzvppdri</li>
               <li>def2qzvpri</li>
               <li>def2qzvppri</li>
               <li>def2qzvppdri</li>
               <li>tzv</li>
               <li>weigend</li>
               <li>weigend+etb</li>
               <li>weigendcfit</li>
               <li>weigendjfit</li>
               <li>demon</li>
               <li>demoncfit</li>
               <li>ahlrichs</li>
               <li>ahlrichscfit</li>
               <li>ccpvtzfit</li>
               <li>ccpvdzfit</li>
               <li>ccpwcvtzmp2fit</li>
               <li>ccpvqzmp2fit</li>
               <li>ccpv5zmp2fit</li>
               <li>augccpwcvtzmp2fit</li>
               <li>augccpvqzmp2fit</li>
               <li>augccpv5zmp2fit</li>
               <li>ccpcvdz</li>
               <li>ccpcvtz</li>
               <li>ccpcvqz</li>
               <li>ccpcv5z</li>
               <li>ccpcv6z</li>
               <li>ccpwcvdz</li>
               <li>ccpwcvtz</li>
               <li>ccpwcvqz</li>
               <li>ccpwcv5z</li>
               <li>ccpwcvdzdk</li>
               <li>ccpwcvtzdk</li>
               <li>ccpwcvqzdk</li>
               <li>ccpwcv5zdk</li>
               <li>ccpwcvtzdk3</li>
               <li>ccpwcvqzdk3</li>
               <li>augccpwcvdz</li>
               <li>augccpwcvtz</li>
               <li>augccpwcvqz</li>
               <li>augccpwcv5z</li>
               <li>augccpwcvtzdk</li>
               <li>augccpwcvqzdk</li>
               <li>augccpwcv5zdk</li>
               <li>augccpwcvtzdk3</li>
               <li>augccpwcvqzdk3</li>
               <li>dgaussa1cfit</li>
               <li>dgaussa1xfit</li>
               <li>dgaussa2cfit</li>
               <li>dgaussa2xfit</li>
               <li>ccpvdzpp</li>
               <li>ccpvtzpp</li>
               <li>ccpvqzpp</li>
               <li>ccpv5zpp</li>
               <li>crenbl</li>
               <li>crenbs</li>
               <li>lanl2dz</li>
               <li>lanl2tz</li>
               <li>lanl08</li>
               <li>sbkjc</li>
               <li>stuttgart</li>
               <li>stuttgartdz</li>
               <li>stuttgartrlc</li>
               <li>stuttgartrsc</li>
               <li>stuttgartrsc_mdf</li>
               <li>ccpwcvdzpp</li>
               <li>ccpwcvtzpp</li>
               <li>ccpwcvqzpp</li>
               <li>ccpwcv5zpp</li>
               <li>ccpvdzppnr</li>
               <li>ccpvtzppnr</li>
               <li>augccpvdzpp</li>
               <li>augccpvtzpp</li>
               <li>augccpvqzpp</li>
               <li>augccpv5zpp</li>
               <li>pc0</li>
               <li>pc1</li>
               <li>pc2</li>
               <li>pc3</li>
               <li>pc4</li>
               <li>augpc0</li>
               <li>augpc1</li>
               <li>augpc2</li>
               <li>augpc3</li>
               <li>augpc4</li>
               <li>pcseg0</li>
               <li>pcseg1</li>
               <li>pcseg2</li>
               <li>pcseg3</li>
               <li>pcseg4</li>
               <li>augpcseg0</li>
               <li>augpcseg1</li>
               <li>augpcseg2</li>
               <li>augpcseg3</li>
               <li>augpcseg4</li>
               <li>sarcdkh</li>
               <li>bfdvdz</li>
               <li>bfdvtz</li>
               <li>bfdvqz</li>
               <li>bfdv5z</li>
               <li>bfd</li>
               <li>bfdpp</li>
               <li>ccpcvdzf12optri</li>
               <li>ccpcvtzf12optri</li>
               <li>ccpcvqzf12optri</li>
               <li>ccpvdzf12optri</li>
               <li>ccpvtzf12optri</li>
               <li>ccpvqzf12optri</li>
               <li>ccpv5zf12</li>
               <li>ccpvdzf12rev2</li>
               <li>ccpvtzf12rev2</li>
               <li>ccpvqzf12rev2</li>
               <li>ccpv5zf12rev2</li>
               <li>ccpvdzf12nz</li>
               <li>ccpvtzf12nz</li>
               <li>ccpvqzf12nz</li>
               <li>augccpvdzoptri</li>
               <li>augccpvtzoptri</li>
               <li>augccpvqzoptri</li>
               <li>augccpv5zoptri</li>
               <li>pobtzvp</li>
               <li>pobtzvpp</li>
               <li>crystalccpvdz</li>
               <li>ccecp</li>
               <li>ccecpccpvdz</li>
               <li>ccecpccpvtz</li>
               <li>ccecpccpvqz</li>
               <li>ccecpccpv5z</li>
               <li>ccecpccpv6z</li>
               <li>ccecpaugccpvdz</li>
               <li>ccecpaugccpvtz</li>
               <li>ccecpaugccpvqz</li>
               <li>ccecpaugccpv5z</li>
               <li>ccecpaugccpv6z</li>
               <li>ccecphe</li>
               <li>ccecpheccpvdz</li>
               <li>ccecpheccpvtz</li>
               <li>ccecpheccpvqz</li>
               <li>ccecpheccpv5z</li>
               <li>ccecpheccpv6z</li>
               <li>ccecpheaugccpvdz</li>
               <li>ccecpheaugccpvtz</li>
               <li>ccecpheaugccpvqz</li>
               <li>ccecpheaugccpv5z</li>
               <li>ccecpheaugccpv6z</li>
               <li>ccecpreg</li>
               <li>ccecpregccpvdz</li>
               <li>ccecpregccpvtz</li>
               <li>ccecpregccpvqz</li>
               <li>ccecpregccpv5z</li>
               <li>ccecpregaugccpvdz</li>
               <li>ccecpregaugccpvtz</li>
               <li>ccecpregaugccpvqz</li>
               <li>ccecpregaugccpv5z</li>
           </ul>
       </div>
   </div>

There are additional dyall basis sets, for which a separate discussion is done in the section ``Additional information on Dyall basis sets``.

**********************
JK auxiliary basis set
**********************

Following is the list of exact keywords of all currently available JK auxiliary basis sets in BAGH. JK basis can only be assigned using universal basis assignment (as in ``pos4`` in Example 1).

.. raw:: html

   <!-- Dropdown Menu HTML -->
   <div class="dropdown">
       <button class="dropdown-btn">Choose JK auxiliary basis</button>
       <div class="dropdown-content" style="display: none;">
           <ul>
               <li>ccpvdzjkfit</li>                                                                               
               <li>ccpvtzjkfit</li>                                                    
               <li>ccpvqzjkfit</li>                                                                                   
               <li>ccpv5zjkfit</li>
               <li>weigendjkfit</li>
               <li>augccpvdzjkfit</li>                                                                                  
               <li>augccpvdzpjkfit</li>                                                                                
               <li>augccpvtzjkfit</li>                                                                               
               <li>augccpvqzjkfit</li>
               <li>augccpv5zjkfit</li>
               <li>heavyaugccpvdzjkfit</li>
               <li>heavyaugccpvtzjkfit</li>
               <li>def2svpjfit</li>
               <li>def2svpjkfit</li>
               <li>def2tzvpjfit</li>
               <li>def2tzvpjkfit</li>
               <li>def2tzvppjfit</li>
               <li>def2tzvppjkfit</li>
               <li>def2qzvpjfit</li>
               <li>def2qzvpjkfit</li>
               <li>def2qzvppjfit</li>
               <li>def2qzvppjkfit</li>
               <li>def2universaljfit</li>
               <li>def2universaljkfit</li>
           </ul>
       </div>
   </div>

**********************
RI auxiliary basis set
**********************

Following is the list of exact keywords of all currently available RI auxiliary basis sets in BAGH. RI basis can only be assigned using universal basis assignment (as in ``pos5`` in Example 1).

.. raw:: html

   <!-- Dropdown Menu HTML -->
   <div class="dropdown">
       <button class="dropdown-btn">Choose RI auxiliary basis</button>
       <div class="dropdown-content" style="display: none;">
           <ul>
               <li>cc-pvdz-ri</li>
               <li>cc-pvtz-ri</li>
               <li>cc-pvqz-ri</li>
               <li>cc-pv5z-ri</li>
               <li>cc-pv6z-ri</li>
               <li>cc-pwcvdz-ri</li>
               <li>cc-pwcvtz-ri</li>
               <li>cc-pwcvqz-ri</li>
               <li>cc-pwcv5z-ri</li>
               <li>cc-pwcv6z-ri</li>
               <li>aug-cc-pvdz-ri</li>
               <li>aug-cc-pvtz-ri</li>
               <li>aug-cc-pvqz-ri</li>
               <li>aug-cc-pv5z-ri</li>
               <li>aug-cc-pv6z-ri</li>
               <li>def2-svp-ri</li>
               <li>def2-tzvp-ri</li>
               <li>def2-qzvp-ri</li>
           </ul>
       </div>
   </div>

.. raw:: html

   <!-- Custom CSS -->
   <style>
       .dropdown {
           margin: 20px 0;
           font-family: Arial, sans-serif;
           position: relative;
           width: 200px;
       }

       .dropdown-btn {
           cursor: pointer;
           background-color: #007bff;
           color: white;
           border: none;
           padding: 10px 15px;
           font-size: 16px;
           border-radius: 5px;
           text-align: left;
           width: 100%;
       }

       .dropdown-btn:hover {
           background-color: #0056b3;
       }

       .dropdown-content {
           position: absolute;
           top: 100%;
           left: 0;
           right: 0;
           max-height: 200px; /* Limits the height of the dropdown */
           overflow-y: auto; /* Adds vertical scrolling */
           border: 1px solid #ddd;
           background-color: #f9f9f9;
           border-radius: 5px;
           box-shadow: 0px 4px 6px rgba(0, 0, 0, 0.1);
           z-index: 1000;
       }

       .dropdown-content ul {
           list-style: none;
           padding: 0;
           margin: 0;
       }

       .dropdown-content li {
           padding: 10px;
           cursor: pointer;
           border-bottom: 1px solid #ddd;
       }

       .dropdown-content li:hover {
           background-color: #e9e9e9;
       }

       .dropdown-content li:last-child {
           border-bottom: none;
       }
   </style>

.. raw:: html

   <!-- Custom JavaScript -->
   <script>
      document.addEventListener("DOMContentLoaded", function() {
          const dropdowns = document.querySelectorAll(".dropdown");
      
          dropdowns.forEach((dropdown) => {
              const dropdownBtn = dropdown.querySelector(".dropdown-btn");
              const dropdownContent = dropdown.querySelector(".dropdown-content");
      
              dropdownBtn.addEventListener("click", function() {
                  const isHidden = dropdownContent.style.display === "none" || dropdownContent.style.display === "";
                  dropdownContent.style.display = isHidden ? "block" : "none";
              });
      
              // Hide dropdown if clicked outside
              document.addEventListener("click", function(event) {
                  if (!dropdown.contains(event.target)) {
                      dropdownContent.style.display = "none";
                  }
              });
          });
      });
   </script>

Uncontraction of the basis sets
###############################

The atom-specific and universal basis sets can be uncontracted by adding a prefix ``unc-`` to the name of the basis set. eg. for an uncontracted version of the ``aug-cc-pVDZ`` basis set, one has to write ``unc-augccpvdz`` in the place of the basis set. See the following example:

Example 10:

.. code-block:: shell 

   ! CCSD spinor unc-augccpvdz

   %cc
   incore 5
   end

   *xyz 0 1
   H	 0.0000	-0.9377	-0.3816
   H	 0.8121	 0.4689	-0.3816
   H	-0.8121	 0.4689	-0.3816 unc-631g
   N	 0.0000	 0.0000	 0.0000

In the custom basis, one can uncontract beforehand if they need it.

Additional information on Dyall basis sets
##########################################