# Twiny - from morphology to twin element and vice versa

Twiny is a small Fortran software for identification or confirmation of the twin element from the morphological analysis of twins.
It takes as input the twin element and computes the angle between corresponding [*uvw*] directions in two individuals of the twin: the result is used by the
investigator to confirm or invalidate the supposed twin element.

Twiny also accepts as input the angle measured on the sample and computes all possible twin elements compatible with such angle: the result helps the investigator to identify the twin element before any attempt to unravel the diffraction pattern of a twin.

The software accepts four options. Options 1. and 2. refer to the case of known twin element; options 3. and 4. refer instead to
the case of unknown twin element but the angle between the corresponding between the corresponding [*uvw*] directions in the twinned individuals is known.

**Reflection twin**: the user enters the (*hkl*) Miller indices of the twin plane and the [uvw] indices of a prominent direction. Twiny calculates the angle δ between [*uvw*] in the two individuals related by (*hkl*).**Rotation twin**: the user enters the [*u*'*v*'*w*'] indices of the twin axis, the type of rotation (2-fold, 3-fold, 4-fold or 6-fold) and the [*uvw*] indices of a prominent direction. Twiny calculates the angle δ between [*uvw*] in the two individuals related by [*u*'*v*'*w*'].**Reflection twin**: the user enters [uvw] indices of a prominent direction and the measured angle δ between [*uvw*] in the two individuals. Twiny estimates the possible twin planes leading to δ.**Rotation twin**: the user enters [uvw] indices of a prominent direction, the measured angle δ between [*uvw*] in the two individuals, and the type of rotation. Twiny estimates the possible twin axis leading to δ.

Zipped archives for download

- Windows version, with installer
- Linux 32 bit version
- Linux 64 bit version
- Macintosh version, MacOS X 10.8

The reprint of the article presenting Twiny can be downloaded here.