Define distance between atoms in different molecules

[Milziade]

Is your feature request related to a problem? Please describe.
It's very difficult to move molecules around the 3D space
For example, for Diels-Alder reaction, I want one reactant over the other at a given distance in order to perform relaxed scan over given coords, but now I have to select my molecule, move it, check the distance and repeat untill achieving the wanted result

Describe the solution you'd like
It would be nice to directly change the distance between two atoms using the Manipulation Tool.
By now you can only change XYZ coods of atoms/molecules with respect to the actual position. A good solution can be change XYZ coods based on another atom (last selected?) coord. (add small menu to define translation between actual position or last/first selected atom)

[ghutchis]

I'm not entirely sure I understand what you want. If the two molecules are not bonded, there are multiple ways to satisfy that distance constraint.

My suggestion would be to set a particular atom at the origin and another along an axis using the Align tool - and then you can move the fragments relative to each other easily along your specified axis.