hegoimanzano/pycsh

pyCSH

pyCSH is a Python code for the automated generation of realistic bulk calcium silicate hydrate (C-S-H) structures, based on the brick model introduced by Kunhi Mohamed et al [1].

[1] A. Kunhi Mohamed, S.C. Parker, P. Bowen, S. Galmarini. An atomistic building block description of C-S-H - Towards a realistic C-S-H model, Cem Concr Res 107 (2018) 221–235. https://doi.org/10.1016/j.cemconres.2018.01.007.

License

Copyright (C) 2024 Jon López-Zorrilla ([email protected]), Ziga Casar

pyCSH is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program; if not, you can obtain it from https://www.gnu.org/licenses/old-licenses/gpl-2.0.html.

Installation and usage

The only requirement for the usage of pyCSH is having access to Python 3, with the Numpy package installed. The executable of the code is main_brick.py:

python3 main_brick.py

The parameters that control the generated CSH models are defined in parameters.py, and are the following:

• seed: Optional. Default : 1123 Seed for the random number generator.

• shape: Required Shape of the supercell of defective tobermorite 14 A. Tuple of the shape (Nx, Ny, Nz).

• Ca_Si_ratio: Required Target Ca/Si ratio of the CSH model.

• W_Si_ratio: Required Target water/Si ratio of the CSH model.

• prefix: Optional. Default: 'input' Name of the output files.

• N_samples: Required Number of structures to be generated.

• make_independent: Optional. Default: False Whether to ensure that none of the structures are different spatial arrangement of the same unit cells or not.

• offset_gaussian: Optional. Default: False If True, some preliminary calculations will be done in order to impose more strictly that the amount of Ca-OH and Si-OH are closer to the experimental values.

• width_Ca_Si: Optional. Default: 0.1 Width of the gaussian used for sampling the Ca/Si ratio of each of the unit cells that compose the total supercell. Smaller values (e.g. 0.01) will lead to ratios closer to the target, but might cause the code to fail.

• width_SiOH: Optional. Default: 0.08 Width of the gaussian used for sampling the Si-OH/Si ratio.

• width_CaOH: Optional. Default: 0.04 Width of the gaussian used for sampling the Ca-OH/Ca ratio.

• create: Required. True if you want to generate new structures, False, if other modes are required. See check and read_structure.

• check: Optional. Default: False If True, a prelimilary check for a wide range of Ca/Si ratios will be performed, in order to show the accuracy of the generated models for the selected parameters with respect to the Ca/Si ratio, water/Si ratio etc.

• read_structure: Optional. Default: False If True, handmade brick code will be read from the end of the parameters file.

  • surface_from_bulk: Optional. Default: False. If True, the handmade structure will be transformed to a surface in the z dimension by adding upper (">Lo", ">Ro") and lower ("<Lo", "<Ro") chains.
  • surface_separation: Optional. Default: False Approximate distance between the layers of CSH surfaces.

• write_lammps: Optional. Default: True Write a .data LAMMPS data file for each of the structures.

• write_lammps_erica: Optional. Default: True Write a .data LAMMPS data file for each of the structures, with core-shell, bonds and angle information to use with EricaFF.

• write_vasp: Optional. Default: True Write a .vasp VASP data file for each of the structures.