C-DNA is produced at 66% relative humidity and in the presence of Li⁺ ions. This form of DNA is known as the right-handed helix with an axial rise of 3.32 Å per base pair. Per turn of the helix contains 9.33 base pairs and the pitch of the helix is, therefore, 3.32 × 9.33 or 30.97 Å. The rotation per base in C-DNA is 360/9 or 38.58 Å. The C-helix has a diameter of 19 Å and the tilt of the base pair is 7.8 Å.