Editing structures

Editing structures#

Editing is enabled by Edit → Editing mode (Ctrl+E). All operations can be undone (Ctrl+Z; redo with Ctrl+Shift+Z or Ctrl+Y), and Edit → Restore geometry (Ctrl+R) returns the structure to the state in which it was read.

Selection#

An atom is selected by clicking it and added to the selection with Ctrl held down; clicking the background clears the selection. Edit → Select all (Ctrl+A), Clear selection and Invert selection act on the whole structure.

Moving atoms#

A selected atom is moved by dragging it; its periodic images move with it, and a selection of several atoms moves as a unit. The arrow keys displace the selection by a small step, and Edit → Translate selected… applies a given displacement.

Adding and removing atoms#

  • Delete selected (Del)

  • Duplicate selected (Ctrl+D)

  • Set element of selected…, which opens a periodic table

The cell#

The Cell menu acts on the lattice rather than on the atoms:

  • Crystallographic cell and Primitive cell select which of the two is displayed.

  • Lattice parameters… edits a, b, c, α, β and γ.

  • Supercell… expands the cell.

  • Complete molecules at cell boundary completes the molecules cut by the edges of the cell. This affects the drawing; the deck written for CRYSTAL contains the cell itself.

  • Point symmetry analysis and Brillouin zone… are described in Symmetry and Band paths.

The Info panel is recomputed after each operation, so the space group shown is that of the current structure.

Measurements#

The Geometry panel measures the current selection:

Atoms selected

Quantity

1

the position of the atom

2

a distance

3

an angle

4

a dihedral angle

3 or more

a least-squares plane

Measurements remain drawn in the view and can be coloured individually or by type.