Home | All Commands | Notice

Home

Dimensions within RasMol

All dimensions in RasMol, such as radii and distances, may be specified in either 'RasMol units' or Ångstroms (Å). The RasMol units were first introduced to allow reasonably sized values to be specified for most of the operations performed in RasMol. A single RasMol unit corresponds to 1/250th of an Ångstrom; therefore the most frequently used values are in the hundreds. For this reason, if RasMol is given a distance parameter that does not contain a decimal point, it is assumed to be in RasMol units. For example, the command 'spacefill 300' specifies a sphere radius of 300 RasMol units, or 1.2 Å.

However, dimensions within RasMol can also be specified in Ångstroms by placing a decimal point in the number. For example, 'spacefill 1.2' specifies a sphere radius of 1.2 Å. This is particularly useful for the cut-off distance parameter in 'within' expressions.