Nanostructure

Step by step

1. Choose the type

   Sheet (graphene or h-BN, width, layers, periodic or a flake with H edges), Nanotube (chirality n, m; length; multi-walled or ropes), Particle (a crystal cut to a sphere, cube, octahedron, fibre …; optional passivation) or Pore (slit, cylinder or from a CIF, with a fluid).

2. Graft functional groups (optional)

   A preset such as carboxyl, or a SMILES with * at the attachment atom; where they go (sidewall, ends, edges); a share of sites or an exact count; a minimum spacing. Graft — undo with ⌘Z. Silane coupling agent grafts silanes onto silanols.

3. Add a polymer matrix (optional)

   Switch on Polymer matrix: the polymer, chains, units per chain and density. The directions the filler fills stay periodic; the rest open up for the chains.

4. Build

   Build sheet, Build nanotube, Build particle or Build pore — or Build composite with the matrix on.

5. Type and relax

   Force field › By group (a carbon or IFF model for the filler, PCFF, COMPASS or OPLS-AA for the polymer), then Minimise: freshly grafted groups can sit close to their neighbours.

The same without the Studio

Every Studio page calls the same core as the caps command and the caps Python package, so a step you clicked can be repeated in a script.

caps nano sheet --lx 20 --ly 20 --layers 1 -o graphene.data
caps nano tube --n 10 --m 10 --length 25 \
    --units '*CC(C)=CC*' --chains 10 --dp 20 --density 0.9 -o cnt_nr.data

from caps import build

tube = build.nano(kind="tube", n=10, m=10, length=25)
tube.save("cnt.data")

Where to go next

PrepareForce fieldType every atom from SMARTS rules, set charges, fill any missing term and give each part of a composite its own force field.PrepareMinimiseRemove close contacts, compress a low-density cell to its target and relax the box.