The part of computational nanotechnology in processing next era of multifunctional substances, molecular level electronic and computing devices, sensors, actuators and machines as explained by a quick review of allowing computational methods and few latest cases gained from computer simulations of carbon nanotube established molecular nanotechnology. The major study aims in molecular nanotechnology are the plans, modeling and production of molecular machines and molecular devices. While the last word objective must clearly be economical fabrication, present capabilities preclude the manufacture of any but the foremost rudimentary molecular structures. More to the purpose , such modeling may be a cheap and straightforward thanks to explore the truly wide selection of molecular machines that are possible, allowing the rapid evaluation and elimination of obvious dead ends and therefore the retention and more intensive analysis of brighter designs. While it are often debated exactly how long it'll fancy develop a broadly based molecular manufacturing capability, it's clear that the proper computational support will substantially reduce the development time. As a result of rapidly increasing computing power to perform large scale and high fidelity simulations, it is becoming increasingly possible for the nanoscale simulations to be also predictive in nature. Computational nanotechnology is emerging as a fundamental engineering analysis tool for novel nanodevices design in a similar way that the continuum finite element analysis (FEA) was and has been used for design and analysis of most of the current generation of engineering systems (e.g., automobiles, ships, airplanes, MEMS devices, and ICs). The accuracies in the atomistic and quantum-mechanical methods have increased to the level, whereby simulations have become truly predictive in nature. From the computer-simulation perspective, the matter is actually multiple length & time-scales in nature. For example, the region of interest for direct simulations extends from the basic atomistic sub-nanometer length scale, to the 10-100s of nanometers in the intermediate range. At the atomistic level, there are accurate semi-classical and quantum molecular mechanics methods that feed into the massive scale classical MD simulations with 10s of millions to few billions of atoms, which then might be coupled to microscopic (micron size) devices and systems described through continuum mechanics or finite element based approaches. Nanotechnology may be a truly a multidisciplinary field, spanning across many core physical sciences and engineering areas. The role of computational nanotechnology because the enabling technology, for conceptualization, characterization, development and prototyping of nanoscale materials, devices and systems applications, is vast and beyond the scope of being fully covered in a single issue.