mofstructure

A Python toolkit for topology, porosity, and building-unit analysis of MOFs

This is an elaborate python module that provides simple functions for manipulation metal-organic frameworks and other porous systems such as COFs and Zeolites. Some uses of the module involves

Features

mofstructure provides tools for:

1. Topology identification

   • Compute framework topology using Systre and RCSR-style net naming when available.

2. Porosity analysis

   • Compute geometric properties such as PLD, LCD, ASA, accessible volume, and channel information.
   • Uses Zeo++/pyzeo-style workflows in the background.

3. Guest removal

   • Automatically remove unbound guest molecules from porous frameworks.

4. Framework deconstruction

   • Deconstruct MOFs into chemically meaningful building units, including:
     • metal clusters
     • organic ligands
     • metal SBUs
     • organic SBUs

5. Cheminformatics for building units

   • Compute identifiers such as:
     • SMILES
     • InChI
     • InChIKey

6. SBU characterization

   • Identify SBU type and the coordination number of the central metal.

7. Periodic wrapping / reconstruction

   • Rebuild or wrap structures across periodic boundaries to remove visualization artefacts caused by PBC fragmentation.

8. Region-based framework partitioning

   • Separate frameworks into regions to support targeted substitution or building-unit manipulation.

9. Open metal site analysis

   • Detect open metal sites and characterize the local metal environment.

---

Installation

Option 1

pip install mofstructure

Option 2

  git clone https://github.com/bafgreat/mofstructure.git mofstructure
  cd mofstructure
  pip install .

Quick start

Run on the commandline

Building units

Simply run the following command on a cif file or any ase readable file format containing a MOF.

mofstructure cif_file

The script will deconstruct the MOF present in the cif file and load the output in a folder called 'MOF_building_units' in the current directory/folder. If you wish to load the output in a specific folder, simply add the path to the folder as follows:

mofstructure cif_file path_to_result_folder

For multiple cif files. Simply run a loop and all the Results will be saved in the

for cifs in ciffiles:
    mofstructure cifs path_to_result

Creating a database

If you have a folder containg many cif files for different MOF, you could easily create a database. To create such a database, simply run the following command.

mofstructure_database ciffolder

Here the 'ciffolder' is the folder containing the cif files. The ouput will be saved in the default folder called 'MOFDb' in the current folder. Again you can choose the path to the save folder by simply listing it at the end of the command.

mofstructure_database ciffolder path_to_result

Compute topology

You can easily compute the topology of a MOF from the commandline. The code will work for both files (cifs, cgd or any ASE input) folders containing files. Still testing the robustness of topology

mofstructure_topology net.cgd

 mofstructure_topology structure.cif

 mofstructure_topology ./folder

You can also decided how the topology should be computed by defining which deconstruction you want. At the moment we have three major methods [all_nodes, sbus and ligand_cluster]. Note that the topology from each could be thesame or different since these methods determines how the topological graph is constructed.

 mofstructure_topology structure.cif --method all_nodels

 mofstructure_topology ./folder ligand_cluster

For a very large dataset you can choose to write files to disk in small batches. for that you can use the --flush-every keyword as follows.

 mofstructure_topology ./folder ligand_cluster --flush-every 100

Use as a libray

from  mofstructure import structure

"""
you can parse in a filename or an ase atom
"""

mof_object = structure.MOFstructure(filename=cif_file)

# once and also directly parse an ASE atom object
# mof_object = structure.MOFstructure(ase_atoms)


guest_free_ase_atoms = mof_object.remove_guest()



# compute porosit and write output to csv
pores = mof_object.get_porosity(probe_radius=1.86, number_of_steps=5000,  rad_file=None,high_accuracy=True)
df = pd.DataFrame(pores, index=[0])
df.to_csv('pore.csv')

sbus and linkers

Compute sbus and linkers

metal_sbus, organic_sbus = mof_object.get_sbu(wrap_system=True, cheminfo=True, add_dummy=False)

organic_ligands = mof_object.get_ligands(wrap_system=True, cheminfo=True, add_dummy=False)

when cheminfo = True

openbabel is called to compute all chemifomatic information, which are all stored on the ase_atom.info metal_sbus and organic_sbus list that contains all the unique instances of the metal sbus and organic sbus.

extracting cheminfor

For each instance in a building unit the various chemiformatic informations are as follows.

for i,  sbu in enumerate(metal_sbus):
    smi = sbu.info['smi']
    inchi = sbu.info['inchi']
    inchikey = sbu.info['inchikey']
    # for sbus only
    number_of_point_of_extension = sbu.info['point_of_extension']
    #for metal sbus only
    sbu_type = sbu.info['sbu_type'] # sbu_type :rodlike, irmof, uoi66, paddlewheel e.t.c
    # write
    sbu.write('metal_sbu_'+str(i)+'.cif')

open metal site, metal coordination number/environment

oms =  mof_object.get_oms()
print(oms)

Topology

topology = mof_object.get_topology()
print (topology )

You can also compute topology directly from systre module incase you wish to have more autonomy

from ase.io import read
from mofstructure.systre import identify_topology

# 1) From a CGD file
res = identify_topology("net.cgd", input_is_cgd=True)
print(res.topology)

# 2) From a CIF (generate CGD then run systre)
res = identify_topology("UiO-66.cif", method="all_node")
print(res.topology)

# 3) From ASE Atoms
atoms = read("UiO-66.cif")
res = identify_topology(atoms)
print(res.topology)

Documentation

You can access the full project documentation on docs

Citation

If you find mofstructure helpful please kindly cite the following manusrcipts

@article{wonanke2026fairmofs,
  title={FAIR-MOFs: Structure-centred synthesis inference from three-dimensional structures of metal-organic frameworks},
  author={Wonanke, Dinga and Heine, Thomas and Longa, Antonio and others},
  year={2026},
  doi={10.21203/rs.3.rs-8375247/v1}
}

Roadmap

In the future the code should be able to:

1. We are currently working on SBU deconstruction and topological analysis of COFs.

Updates version 0.1.8.6

This release introduces a major upgrade to the topology analysis workflow in mofstructure, providing a more robust, reproducible, and information-rich framework for topological characterization.

Key improvements

1. Enhanced topology extraction

Topology determination is now handled through a high-level interface built on top of Systre, enabling:

• Direct support for:
  • .cgd files
  • CIF and all ASE-readable structure formats
  • Batch processing of folders
• Automatic generation of CGD representations when needed
• Improved robustness for complex and multi-component frameworks

---

2. Rich topology output

The get_topology() method now returns a structured dictionary containing:

• topology → Identified RCSR net (or UNKNOWN)
• dimension → Periodicity of the net (0D, 1D, 2D, 3D)
• td10 → Topological density descriptor from Systre
• topology_hash → Stable hash of the relaxed topology
• cgd_crystal2text → CRYSTAL2 representation of the relaxed net

This enables reproducible identification and easy downstream storage/indexing.

---

3. Relaxed-topology hashing

A deterministic topology hash is now available:

• Based on normalized relaxed coordinates
• Independent of atom ordering and numerical noise
• Suitable for:
  • database indexing
  • duplicate detection
  • large-scale screening workflows

---

4. CRYSTAL2 export from relaxed topology

The topology pipeline now supports:

• Direct generation of CRYSTAL2-style CGD text from relaxed Systre output
• Optional inclusion of edge-center metadata
• Fallback conversion from original CGD when relaxed output is unavailable

---

5. Memory-efficient workflow

The topology computation has been redesigned to be lightweight:

• Uses a single Systre call per structure
• Avoids redundant parsing and data duplication
• Only extracts the most informative component by default

This makes it suitable for large MOF datasets and high-throughput workflows.

---

6. Improved CLI support

Topology tools now:

• Work seamlessly on files and folders
• Support CSV/JSON export of results
• Provide optional verbose output for debugging
• Maintain backward compatibility with legacy flags

---

Example

from mofstructure import structure

mof = structure.MOFstructure(filename="UiO-66.cif")
topo = mof.get_topology()

print(topo)

Updates version 0.1.7

1. Implemented a robust CI/CD using git actions
2. Included add_dummy key to add dummy atoms to point of extension. This is important to effectively control the breaking point. This dummy atoms can then be replaced with hydrogen to fully neutralize the system.

N.B

Be please don't use add dummy when deconstructing to ligands and clusters. The add dummy argument should be used only for sbus. e.g

connected_components, atoms_indices_at_breaking_point, porpyrin_checker, all_regions, breaking_pairs = MOF_deconstructor.secondary_building_units(ase_atom)
metal_sbus, organic_sbus, building_unit_regions = MOF_deconstructor.find_unique_building_units(
    connected_components,
    atoms_indices_at_breaking_point,
    ase_atom,
    porpyrin_checker,
    all_regions,
    cheminfo=True,
    add_dummy=True
    )

metal_sbus[0].write('test1.xyz)

Updates version 0.1.6

Added new command line tools to expedite calculations especially when working on a quite large database.

compute only deconstruction

If you wish to only compute the deconstruction of MOFs without having to compute their porosity and open metal sites. Then simply run the following command

mofstructure_building_units  cif_folder

compute only porosity

If you wish to only compute the porosity using default values. i.e probe radius = 1.86, number of gcmc cycles = 10000 and default csd atomic radii, then run the following command:

mofstructure_porosity cif_folder

However, if you wish to use another probe radius of maybe 1.5 and gcmc cycles of 20000 alongside custom atomic radii in a file called rad.rad, run the following command:

mofstructure_porosity cif_folder -pr 1.5 -ns 20000 -rf rad.rad

compute only open metal sites

If you are only interested in computing the open metal sites, then running the following command

mofstructure_oms cif_folder

Updates version 0.1.5

The new update enables users to include a Rad file when computing porosity using pyzeo. This allows users to specify the type of radii to use. If omitted, the default pyzeo radii will be used, which are covalent radii obtained from the CSD.

Currently, this functionality can only be used when using mofstructure as a library. This can be done as follows:

from mofstructure.porosity import zeo_calculation
from ase.io import read

ase_atom = read(filename)

pore_data = zeo_calculation(ase_atom, rad_file='rad_file_name.rad')

NB

Note that filename is any ASE-readable crystal structure file, ideally a CIF file. Moreover, rad_file_name.rad is a file containing the radii of each element present in the structure file. This should be formatted as follows:

element radii

For example, for an MgO system, your Rad file should look like this:

Mg 0.66
O 1.84

Also note that of the radii file does not have the .rad extension like rad_file_name.rad the default radii will be used.

Updates version 0.1.4

The new update enables the computation of open metal sites in cifs To use this functionality run the following on the command line

mofstructure_database ciffolder --oms

Here ciffolder corresponse to the directory/folder containing the cif files.

After the computation the metal information will be found in a json file called metal_info.json. This file is found in the output folder that defaults to MOFDb incase none is provided.

NB

Note that computing open metal sites is computationally expensive, especially if you intend to run it on a folder with many cif files. There I recommend that if you are not interested in computing the open metal sites simply run command without the --oms option.

mofstructure_database ciffolder

This command will generate a MOFDb folder without the metal_info.json file. But the code will run very fast.

Also note that the --oms option is provided on for the mofstructure_database command. This is not available for mofstructure command which targets a single cif file. If you have a single cif file wish to compute open metal sites, simply put the cif file in a folder and rin mofstructure_database command on the folder (mofstructure_database ciffolder --oms).