Effectively Specifiying Spacegroup Sampling for Organic CSP

[JennieEMartin]

Hi,

I have a few questions/suggestions regarding the use of the dictionaries to specify the spacegroup sampling/constraints used structure generation/ranking methods. I am coming at this from the area of Organic CSP, but am unsure if the same queries/concerns would be applicable to other areas of CSP.

The first question regards specifying different extents of sampling in different spacegroups. Currently, when looking at the structure generation category it appears that you can provide a list of multiple sampled spacegroups via space_group_number_list, but when it comes to specifying a stopping criterion, stopping_criteria_max_structures_evaluated or _csp.random.number of samples are intended only to take a single number as their values, meaning it is difficult to simply specify a sampling scheme in which differnet numbers of structures are sampled in each spacegroup.

One solution could be to write a loop specifying each spacegroup(s) using followed by its corresponding max structures sampling, for example:

loop_
    _csp.structure_generation.space_group_number_list
    _csp.structure_generation.stopping_criteria
    _csp.structure_generation.stopping_criteria_max_structures_evaluated
   
    [1 61 19]  "Max Stuctures Reached" 1000
    [4 33]   "Max Stuctures Reached"  2000

However, its not quite clear to me from the examples/documentation if this would be accepted within the conventions the community is seeking to develop. Is this a suitable way of specifying the sampling? Similarly, its perhaps not 100% clear from the descriptions whether (if a loop was not used) a single provided stopping_criteria_max_structures_evaluated would refer to the total across the spacegroups or the total in each spacegroup?

Secondly, in the structure ranking or geometry optimisation category it would be useful to be able to specify if symmetry is contrained during optimisation. This would affect whether the spacegroup can change during the optimisation. For example, specifying something like:

 _geometry_optimisation.constrained_symmetry True

Lastly, when using workflows that do not constrain spacegroup symmetry at all ranking stages, it could be useful in a structure .cif to be able to specify the original spacegroup in which the structure was generated during the structure generation stage. E.g

_predicted_structure.initial_spacegroup 15

Many Thanks. Please let me know if anything is unclear or if you'd prefer me to pose these questions elsewhere

[nicholasfrancia]

Hi! Thank you for these suggestions!
Some prefix labels have been updated following the October meeting, but we have added the data fields _compchem.geometry_optimisation_constrained_symmetry and _theoretical_structure.csp_initial_spacegroup, which are equivalent to the suggestions you provided.

For the stopping criteria data fields, we added the data field _csp.structure_generation_stopping_criteria_space_group_number_list to be used in a loop.
The data field _csp.structure_generation_stopping_criteria_max_structures_evaluated is the same, but to keep it consistent with its use outside of a loop, it refers to the total number of structures within the subset.

We added these examples in the cspcore.md file to clarify it better:

# Random Search 1
data_rs
    _csp.data_block_class                                                "Generation Method"
    _csp.data_block_description                                          rs
    _csp.data_block_id                                                   8e0147be-0k54-44a1-a3bb-de7df26ddeer
    
    _csp.structure_generation_method                                     "Random Search"
    _csp.random_search_random_numbers_algorithm_type                     "Quasi-random"
    _csp.random_search_random_numbers_algorithm                          "Sobol"
    
    _csp.structure_generation_space_group_number_list                    [14 2 15 61 19 4 33 29 5 1]
    _csp.structure_generation_stopping_criteria_description              "Max Structures"
    loop_
        _csp.structure_generation_stopping_criteria_space_group_number_list                         
        _csp.structure_generation_stopping_criteria_max_structures_evaluated  
        14   1000  # 1000 structures for each spacegroup
        2    1000
        15   1000
        61   1000
        19   1000
        4     500
        33    500
        29    500
        5     500
        1     500      


# Random Search 2
data_rs2
_csp.data_block_class                                                "Generation Method"
    _csp.data_block_description                                          rs2
    _csp.data_block_id                                                   6e0147be-0454-44a1-a3bb-de7b326dde1b
    
    _csp.structure_generation_method                                     "Random Search"
    _csp.random_search_random_numbers_algorithm_type                     "Quasi-random"
    _csp.random_search_random_numbers_algorithm                          "Sobol"
    
    _csp.structure_generation_space_group_number_list                    [14 2 15 61 19 4 33 29 5 1]
    _csp.structure_generation_stopping_criteria_description              "Max Structures"
    loop_
        _csp.structure_generation_stopping_criteria_space_group_number_list                      
        _csp.structure_generation_stopping_criteria_max_structures_evaluated  
        [14 2 15 61 19]  5000 # 5000 structures in total, not necessarily equally distributed
        [4 33 29 5 1]    2500    
       

# Simulated Annealing
data_sa
    _csp.data_block_class                                                "Generation Method"
    _csp.data_block_description                                          sa
    _csp.data_block_id                                                   95f28b3c-d029-4840-a69a-3ced34219c28
    
    _csp.structure_generation_method                                     "Simulated Annealing"
    _csp.structure_generation_space_group_number_list                    [14 2 15 61 19 4 33 29 5 1]
    _csp.structure_generation_stopping_criteria_description              "Max Structures"
    _csp.structure_generation_stopping_criteria_max_structures_evaluated 2000000  
    _csp.simulated_annealing_initial_temperature                         400
    _csp.simulated_annealing_cooling_rate                                0.95
    _csp.simulated_annealing_number_of_steps                             100

The data field stopping_criteria_max_structures_evaluated indicates the total number of structures generated across
the different space groups specified into the structure_generation_space_group_number_list or
structure_generation_stopping_criteria_space_group_number_list. In the three Generation Method datablocks, we show
the use of stopping_criteria_max_structures_evaluated data fields:

1. In the first Random Search approach (Datablock 1), for the space groups 14, 2, 15, 61 and 19, the criterion is
   set to 1000 structures each, while for 4, 33, 29, 5 and 1, it is set to 500 structures each, resulting in a total
   of 7500 structures.
2. In the second Random Search approach (Datablock 2), 5000 and 2500 structures are generated in total for subsets
   [14, 2, 15, 61, 19] and [4, 33, 29, 5, 1], respectively, for a total of 7500 structures. Contrary to the previous
   example, these are not necessarily equally distributed among the spacegroups of the subset.
3. In the Simulated Annealing approach (Datablock 3), the value represents the maximum total number of structures
   evaluated across all space groups combined. The search stops when this limit is reached, regardless of how many
   structures were evaluated in any specific space group.

Please let me know if this works and/or if you have any other suggestions.
Thanks again!
Nicholas