# First steps

## Opening a file

**File → Open…** ({kbd}`Ctrl+O`) reads a CRYSTAL output (`.out`), a geometry
file (`.gui`, `.34`) or a crystallographic information file (`.cif`). A file
dropped on the window is opened in the same way.

If the output contains a vibrational calculation, the modes are read with it.
If it does not, the geometry alone is shown and the remaining functions are
unaffected.

## Working in the calculation's folder

CRYSTAL writes more than the output file. A properties run leaves `BAND.DAT`,
`DOSS.DAT`, `fort.25` and their named variants; an anharmonic run leaves
`ANSCANWF.DAT`; the decks that produced them stay as `.d3` files.

CRYSTALLine looks for these beside the output that is open, and works better
when they are all in one folder:

- The **Electronic bands & DOS** dialog lists the band and density-of-states
  files it finds there, recognises them by their contents rather than their
  names, and pairs a band structure with a density of states computed from the
  same SCF.
- It also reads the `.d3` deck that produced the path, which is where the names
  of its corners come from — a band file records coordinates, and for some
  paths not even those.
- The file dialogs of the other plots open in that folder.
- Anharmonic wavefunctions are found without being asked for.

So keeping a calculation and everything it produced in one directory, rather
than moving the output somewhere on its own, is what allows the program to
offer the right file instead of an empty dialog.

## The main window

![The main window](screen1.png)

The window is divided into dockable panels:

| Position | Panel | Contents |
| --- | --- | --- |
| Left | **Info** | space group or layer group, lattice parameters, density, and a summary of the calculation |
| Left | **Display** | the settings of the 3D view |
| Left | **Geometry** | distances, angles, dihedrals and planes |
| Right | **Phonons** | the list of vibrational modes and the animation controls |
| Bottom | **Plots** | the property plots, in tabs |

Panels can be moved, stacked, resized or closed. **View → Panels** restores a
single panel and **View → Restore all panels** restores the original
arrangement.

## Controlling the view

The structure is rotated by dragging, zoomed with the scroll wheel and
translated by dragging with the middle button (or with {kbd}`Shift` held down).

The toolbar contains three groups: **VIEW**, which orients the structure along
the **a**, **b** or **c** axis and returns it to a view of the whole;
**ROTATE**, which turns it by a fixed step, 15° unless changed in the adjacent
box; and **CONV. CELL**, which switches between the crystallographic and the
primitive cell.

**View → Appearance** selects the light or dark interface, or follows the
system setting.

## Next

[The 3D view](viewer.md) describes the Display panel, [Editing
structures](editing.md) the modification of a structure, [Symmetry](symmetry.md)
the analysis and reduction of its symmetry, [Phonons](phonons.md) the
vibrational modes, [CRYSTAL input builder](inputs.md) the preparation of new
calculations and [Property plots](plots.md) the plotting of the results.