The deMon program (http:deMon-software.com) system was developed for density functional theory (DFT) calculations of atoms, molecules and solids. It's first widely available version appeared in 1992. It was based on the Ph.D. work of A. St-Amant performed under the supervision of D.R. Salahub at the Université de Montréal. The beta-release of this version appeared 1993. It also served as the basis for the deMon-KS series of programs developed in Montreal until 1997. The focus of this program development was mainly towards molecular property calculations with LCGTO DFT methods. Remarkable progress was achieved for the calculation of nuclear magnetic shielding tensors and excited states via time-dependent DFT. The calculation of many one-electron properties like electrostatic potentials, nuclear quadrupole coupling constants and others were realized, too. A drawback of the first deMon-KS release, deMon-KS1, was its rather bad self-consistent field (SCF) convergence. At that time it was not obvious if this was due only to technical problems or if the used fitting of the Coulomb and exchange-correlation potential represented a fundamental problem for the SCF convergence. However, it had already been proven that the energy gradients were not variational due to the least-square fit of the exchange-correlation potential according to Sambe and Felton.
Paralel versions of deMon program were developed in Montpellier by Annick Goursot, in Stockholm by Lars G. M. Petterson and in Hannover by Andreas M. Köster. In the innovative environment that the first workshop of the deMon developers was hold in Ottawa, Canada, in March of 2000. In this workshop there was a consensus to join all the codes unifying the functionalities and improvements of the all groups envolved. In the subsequent meetings of this community have been used to discuss the structure of the code and exchange ideas and developed algoritms. The increasing interest of the scientiphic community for the code and the methodological developments lead lars Petterson, in 2003, Stockholm, Sweden, to promote the first international workshop on density functional theory – present and future challenges. Since this time, the aim of the workshop is the discussion of aspects related to the development and implementation of computational codes related to the density functional theory.
The workshop has served to promote the exchange of information favoring scientific collaborations, new developments and applications in systems of increasing complexity and of technological interest. In 2009, the IX workshop was hold in Pune, India, and aspects related to the SCF stability and developments in the field of time dependent DFT (excited state calculations), NMR, and hyperpolarizabilities were discussed.
In 2010, the X deMon developers workshop and International Workshop on Density Functional Theory – Present and Future Challenges will be held in Belo Horizonte, Brasil under the coordination of Prof. Hélio A. Duarte.
In this edition, the workshop will be focused in the development of tools that permit the investigation of complex systems related to the nanotechnology and advanced materials. Some of these tools are linked to the DFT approximate methods (such as DFTB), hybrid QM/MM and QM/QM' methods, large scaling calculations and spectroscopy.