a program to compute non-spherical atomic scattering factors for organic crystals
DiscambMATTS2tsc is a program built upon the new version of DiSCaMB library [1] and computes non-spherical atomic scattering factors from multipolar model [2] parametrized using MATTS databank (databank of Multipolar Atom Types from Theory and Statistical clustering [3]; successor of UBDB databank) and prints them to the .tsc file [4]. The .tsc file from discambMATTS2tsc facilitate crystal structure TAAM refinement [5].
References:
- [1] Chodkiewicz et al., J. Appl. Cryst., 2018, 51, 193-199
- [2] Hansen & Coppens, Acta Cryst. A, 1978, 34, 909-921
- [3] Jha, et al., J. Chem. Inf. Model., 2022, 62, 3752-3765; Rybicka, et al., J. Chem. Inf. Model., 2022, 62, 3766–3783
- [4] Midgley et al., arXiv:1911.08847 ; Kleemiss et al., Chem.Sci., 2021, 12, 1675-1692
- [5] Jha et., al., Acta Cryst. B, 2020, B76, 296-306; Gruza, et al., Acta Cryst. A, 2020, 76, 92-109
DiscambMATTS2tsc is available free of charge for non-commercial use, provided its use is acknowledged. All users have to fill the form (link to form) and agree to the license terms (link to license) to obtain the link to download discambMATTS2tsc.
DiscambMATTS2tsc is also available for commercial use under a separate agreement. Please contact us for details.
For more informations look into the README file.
Non-spherical atomic scattering factors are computed only for light elements (C, H, N, O, F, S, P, Cl,Br). For other elements, and for unrecognized atom types, spherical scattering factors are assigned within Independent Atom Model approach, either from multipolar model (elements up to Z=<36) or from International Tables (elements with Z>36). Spherical multipolar model means: Pval like for neutral atom, Plm = 0, kappa1 & kappa2 = 1.0, with exception of hydrogen atom for which kappa1=1.16 is assigned. For any missing/non assigned atom type please look into the discambMATTS2tsc.log file. For more details see the example of missing atom type.
DiscambMATTS2tsc computes X-ray scattering factors by default. To obtain manually electron scattering factors please type: discambMATTS2tsc.exe -e. DiscambMATTS2tsc runed in automatic mode via NoSpherA2 in Olex2 will switch to computing electron scattering factors automatically, on the basis of the radiation wave length given in the .ins file.
Currently only the olex2.refine with NoSpherA2 from the Olex2-1.3 version and higher and Jana2020 are able to read .tsc file and apply it in the refinement.
Disordered molecules and organometallic molecules are properly handled only when NoSpherA2 in Olex2 is used in automatic mode.
If you have any problems with discambMATTS2tsc, you find a bug or some atom type is missing please contact us via discamb@uw.edu.pl.
If you use discambMATTS2tsc in your work please cite:
- Chodkiewicz et. al., J. Appl. Cryst., 2018, 51, 193-199
Hansen & Coppens, Acta Cryst. A, 1978, 34, 909-921
Jha, et al., J. Chem. Inf. Model., 2022, 62, 3752-3765
Rybicka, et al., J. Chem. Inf. Model., 2022, 62, 3766–3783
DiSCaMB
ver. 2018
DiSCaMB ver. 2018 is a C++ library for calculation of structure factors from the Hansen-Coppens multipolar model of crystal electron density featuring parallel implementation for multicore processors and graphic processing units.
Source code authors: Michal Chodkiewicz & Szymon Migacz
Contact: mchodkiewicz@chem.uw.edu.pl
People involved in the project: Michał L. Chodkiewicz, Szymon Migacz, Witold Rudnicki, Anna Makala, Nigel W. Moriarty, Ralf W. Grosse-Kunstleve, Pavel Afonine, Jarosław Kalinowski, Paul D. Adams, Paulina M. Dominiak
Current developments
To see our current developments, please visit discamb-project on GitHub. Link here.