open-Qmin#

Fast, scalable, customizable software for Landau-de Gennes numerical modeling of nematic liquid crystals and their topological defects

Overview#

Open-Qmin is an open-source code base for numerical modeling of nematic liquid crystals and their topological defects at equilibrium, by relaxation of a finite-difference lattice discretization of the Landau-de Gennes free energy. This project aims to be:

  • Fast: Allows utilization of GPU or CPU resources, and uses efficient minimization routines like the Fast Inertial Relaxation Engine (FIRE).

  • Scalable: Automates MPI parallelization, allowing users to exploit as many CPU cores as they have available in order to access supra-micron scales often closer to experimental dimensions.

  • Customizable: Users can specify boundary conditions, external fields, and material properties, usually without requiring recompilation. Common boundaries like planar walls or colloidal inclusions can be added with provided recipes; or users can define custom boundary geometries site-by-site.

A peer-reviewed article in Frontiers in Physics describes open-Qmin’s theoretical approach, numerical implementation, and basic usage. Some information is more up-to-date in the documentation you’re reading here.

Citation#

If you use open-Qmin for a publication or project, please cite:

Daniel M. Sussman and Daniel A. Beller. “Fast, scalable, and interactive software for Landau-de Gennes numerical modeling of nematic topological defects.” Frontiers in Physics 7 204 (2019). DOI: 10.3389/fphy.2019.00204

Other peer-reviewed papers using open-Qmin#

  • C. Long, X. Tang, R. L. B. Selinger, and J. V. Selinger. “Geometry and mechanics of disclination lines in 3D nematic liquid crystals.” Soft Matter 17: 2265 (2021). DOI: 10.1039/D0SM01899F

  • A. Modin, B. Ash, K. Ishimoto, R. L. Leheny, F. Serra, and H. Aharoni. “Tunable three-dimensional architecture of nematic disclination lines.” Proceedings of the National Academy of Sciences 120: e2300833120 (2023). DOI: 10.1073/pnas.2300833120

  • G. Park, Y.-S. Choi, S. J. Kwon, D. K. Yoon. “Planar Spin Glass with Topologically Protected Mazes in the Liquid Crystal Targeting for Reconfigurable Micro Security Media.” Advanced Materials 36: 2303077 (2023). DOI: 10.1002/adma.202303077

  • H. S. Yun, Z. C. Meijs, G. Park, Y. Fu, L. Isa, D. K. Yoon. “Controlling liquid crystal boojum defects on fixed microparticle arrays via capillarity-assisted particles assembly.” Journal of Colloid and Interface Science 645: 115 (2023). DOI: 10.1016/j.jcis.2023.04.100

Authors#

open-Qmin is developed as a collaboration between the research groups of Daniel Sussman (Emory University) and Daniel Beller (Johns Hopkins University). We very much welcome users to contribute to the project and to tell us how you’re using open-Qmin and how it might be improved.

Acknowledgements#

The first release of open-Qmin was supported by

  • National Science Foundation Grant POLS-1607416

  • Simons Foundation Grant 454947

  • NVIDIA Corporation

  • XSEDE Grant NSF-TG-PHY190027

  • The Multi-Envrionment Computer for Exploration and Discovery (MERCED) cluster at UC Merced, funded by NSF grant ACI-1429783

Ongoing development is supported by

  • National Science Foundation Grant DMR-2046063