Open source · CAPS 0.1.0 · BSD 3-Clause
Polymers and materials, from a SMILES string to a methods section.
CAPS builds molecules, chains, crystals, surfaces and composites; types them with the force field you choose; relaxes, runs and crosslinks them; coarse-grains them; prepares DFT surface studies; and writes every step down so the result can be reproduced and cited.
How a project flows
Six stages, left to right. Each opens a module with its own step-by-step guide.
Three ways in, one core
The Studio, the command line and Python call the same C++ core, so a step clicked in the Studio can be repeated in a script.
CAPS Studio
The desktop app: build, look, run and analyse with live views. Every module is explained step by step.
Module guides →Command line
caps grow, caps relax, caps react … one command per task, for scripts and clusters.
Python
import caps: open and build structures, assign force fields, run, crosslink, analyse and export.
# grow 4 polystyrene chains, relax, run and analyse $ caps grow -o ps.data --chains 4 --dp 10 --density 0.5 --units '*CC(*)c1ccccc1' --seed 1 $ caps relax ps.data -o ps_min.data --quiet $ caps md ps_min.data -o ps_md.data --steps 2000 --barostat berendsen --dump ps.lammpstrj --every 200 $ caps analyze ps.lammpstrj --topology ps_md.data --props density,rg # the same cell for LAMMPS and GROMACS with OPLS-AA $ caps ff type ps_md.data --ff opls2005 -o types.txt $ caps ff apply ps_md.data --ff opls2005 --types types.txt -o ps.data --lammps-input ps.in --gromacs ps wrote ps.top, ps.gro and ps.mdp
Download
Installers for each release are on GitHub. CAPS is free and open source.
CAPS-0.1.0-macos-arm64.dmg
WindowsWindows 10/11, x64. Installer or portable zip.CAPS-0.1.0-windows-x64-setup.exe
LinuxUbuntu/Debian package, AppImage or tarball.caps-studio_0.1.0_amd64.deb
| System | Install | The caps command |
|---|---|---|
| macOS (Apple silicon) | Open the .dmg and drag CAPS Studio to Applications | /Applications/CAPS Studio.app/Contents/MacOS/caps; link it onto your PATH (below) |
| Windows 10/11 (x64) | Run the -setup.exe, or unpack the portable .zip | caps.exe in the install folder; tick Add the caps command line to PATH in the installer |
| Ubuntu / Debian | sudo apt install ./caps-studio_0.1.0_amd64.deb | /usr/bin/caps |
| Any Linux (Arch, Fedora …) | The .AppImage (needs FUSE 2), or the .tar.gz | the tarball's caps, or ./CAPS-…AppImage --appimage-extract and squashfs-root/usr/bin/caps |
# macOS: put caps on your PATH
sudo ln -sf "/Applications/CAPS Studio.app/Contents/MacOS/caps" /usr/local/bin/caps
caps # the usage: every command on one screenThe force-field library, typing rules, samples and presets ship with the program and are found beside it; set
CAPS_HOME only to use a different copy. The Python package is in the program's data/python
folder (see Python setup).
Documentation
Guides for the Studio, the command line and Python, plus the theory behind every method.
import caps: open and build structures, assign force fields, run, crosslink, analyse and write pipeline steps.
Typical routes
Most projects follow one of these chains; each link is a module in the Studio, a command, or a Python call.
Amorphous polymer
Crosslinked network
Coarse-grained model
DFT surface study
Reproducible study