OHCD-IV is a unique apparatus for growing single crystals in capillaries under controlled conditions applying a miniature zone melting procedure. It allows choosing well-defined settings for crystal growths with automated software con-trolled conditions, with repeated scans for

purifying, with positional shifts, varying temperature gradients and speeds, but without breaking the capillary, without creating turbulences with icing, without obscuring the crystallization zone and without the need of a permanent inter-ference. Capillaries are filled with substances, sealed, mounted at a single crystal diffractometer and cooled with an LT device.


A focused IR laser (with hard- and software limits for maximum power, 10640 nm) is directed towards the capillary, and after running the growth program the crystal quality is checked by means of X-ray scattering.

Substances you never thought to determine the crystal structures of, can often be easily crystallized. Gases like acetylene, propane or ammonia, sealed in the capillary can be crystallized and are accessible for structure determination; co-crystals, liquid crystals or ionic liquids, sensitive compounds and explosives, plastic phases and solutions can be investigated, there is a huge playground for the new field of cryo-crystallography.

The compact controller (110/220 V 50/60 Hz) accommodates all necessary hard-ware components and is connected via USB to a computer, running with Win7 and Win10. The optical bench with a visible pilot laser has been adapted to different models of diffractometers, using the cabinet for protection from the laser light..