Zyvex researchers with Robert Freitas and Ralph Merkle have published an important computational chemistry paper, showing dimer placement works reliable at room temperature. (Jing Ping Peng, freitas, merkle, von Ehr, Randall, Skidmore paper on diamond mechnosynthesis) Theoretical analysis of Diamond Mechanosynthesis III : Positional C2 Deposition on Diamond C(110) Surface using Si/Ge/Sn-based dimer placement tools.
The Germanium version of the DBC6 dimer placement tool had detailed computer simulations performed showing that it should work reliably at room temperature. There is no problem placing dimers with a one dimer gap. Placing them directly adjacent can cause some defect formation.
The paper also describes using a first pass of placing every other dimer. Then adding the skipped dimers. This process is a defect-reduced procedure for fully populated dimer rows.
The simulations also showed the maximum placement tolerances. 0.5 angstroms in X (or across dimension) and 1.0 angstroms in the Y (or along trough) for an isolated dimer.
1.0 angstrom in the X and 0.3 angstroms in the Y for a correct gapped dimer placement.
There is a table which shows the tolerances and positional uncertainty at different temperatures using the different materials for tooltips.