A container for multiple pharmacophore definitions 1.0 A SMARTS based representation of a pharmacophore group. This element should have a label attribute, whose value is a string limited to the alphanumeric characters. The label will be used to refer to the group in the constraint definitions. The content of this element should be a valid SMARTS pattern This element represents a distance constraint between two pharmacophore groups. The default unit is angstroms. Currently any distance value can be supplied, though zero negative values are meaningless. By specifying just the lower value the constraint is exact and by specifying both the lower nd upper values one gets a distance range. The constraint is defined between two pharmacophore groups so the contents of this element should 2 groupRef elements with the appropriate ID's, which should have been defined previously. A nm pm radians degrees