CRYSTAL CLEAR - A MOLECULAR CAD TOOL

Molecular nanotechnology requires computer-based design and analysis t ools. Currently they are needed-as part of a computational approach to nanotechnology-to allow detailed, analysed designs to be presented an d discussed and to dovetail with efforts to develop fabrication capabi lities. In the longer term, as fabrication capabilities emerge, they w ill be needed for similar reasons as are needed in today's manufacturi ng systems: to allow investigation of design alternatives and to contr ol manufacturing systems. Given the huge number of 'parts' which may b e required in molecular machines the need for computer-based tools wil l, however, be even more primary for molecular nanotechnology than for today's manufacturing technology, surpassing the CAD requirements of VLSI. Whilst molecular CAD clearly shares some traits with existing CA D, a fundamental difference is that the position and bonding of every atom is of key interest in molecular manufacturing. This necessitates new approaches and techniques. Molecular manufacturing will eventually use diamondoid materials; materials which are crystalline. Molecular CAD tools for the design of diamondoid structures must incorporate tec hniques for manipulating crystalline materials. In this paper, we desc ribe a molecular CAD tool-Crystal Clear-which allows the design of sim ple diamondoid structures in full atomic detail using some novel techn iques based on the crystalline nature of diamondoid materials.