Abstracts for ADF2005 seminar

Session title: Overview of the Amsterdam Density Functional Software Package & Release ADF2005

Speaker 1: Dr. Stan van Gisbergen, Scientific Computing & Modelling N.V., Chief Executive Officer

Title: Overview of ADF and new developments in the ADF2005 release

Abstract: The Amsterdam Density Functional (ADF) program is leading software for quantum chemistry research using Density Functional Theory (DFT). It offers molecular properties and environments for (almost) any molecule and excels at transition metal and heavy element compounds. The ADF2005 release offers

• speed improvements
• new methods for transition state search, geometry optimization, and frequency calculations
• extended output visualization.

A general overview will be given, highlighting the strengths of the ADF software package. The emphasis will be on features that set ADF apart from other density functional programs. The latest improved version of the ADF-Graphical User Interface will be demonstrated. (http://www.scm.com/News/ADFGUIbeta.html, http://www.scm.com/Demos ) The talk is intended as an overview for those who do not know ADF yet, but will also contain new information of interest to current ADF users.

Speaker 2: Dr. Matthias Bickelhaupt, Theoretical Chemistry, Vrije Universiteit, Amsterdam, The Netherlands

Title: Insight and Improved Molecular Design with ADF.

Abstract: This presentation addresses the unique features of ADF that enable a detailed understanding of how the electronic structure determines important molecular properties, such as shape, stability and reactivity. We start out with a brief overview of the theoretical background of Kohn-Sham DFT, followed by a detailed discussion and evaluation of the various tools in ADF for analyzing the chemical bond and electronic structure. The theory will be exemplified by recent case studies that demonstrate how the theory is brought into practice.

Further Reading:
[1] F. M. Bickelhaupt, E. J. Baerends, "Kohn-Sham Density Functional Theory: Predicting and Understanding Chemistry", In: Rev. Comput. Chem.; K. B. Lipkowitz, D. B. Boyd, Eds.; Wiley-VCH: New York, 2000, Vol. 15, pp. 1-86.
[2] G. te Velde, F. M. Bickelhaupt, E. J. Baerends, S. J. A. van Gisbergen, C. Fonseca Guerra, J. G. Snijders, T. Ziegler, "Chemistry with ADF", J. Comput. Chem. 2001, 22, 931-967.
[3] C. Fonseca Guerra, J.-W. Handgraaf, E. J. Baerends, F. M. Bickelhaupt, "Voronoi Deformation Density (VDD) charges. Assessment of the Mulliken, Bader, Hirshfeld, Weinhold and VDD methods for Charge Analysis", J. Comput. Chem. 2004, 25, 189-210.

Speaker 3: Dr. Marcel Swart, Vrije Universiteit, Amsterdam, The Netherlands

Title: Applications of ADF: NMR of DNA, accuracy of geometries, and polarizabilities

Abstract: We will report the application of the ADF program to a number of systems and properties that are of chemical and scientific importance. The first example deals with DNA and RNA base pairs. An experimental study suggested a correlation between NMR data and the hydrogen-bond strength of DNA versus RNA. By using the fragment approach (see previous talk by dr. Bickelhaupt) for obtaining the BSSE-corrected hydrogen-bonding energy, and the NMR property program within the ADF package, we showed the correlation to be nonexistent. [1] The difference in hydrogen-bond energy and NMR parameters were shown to result from two different substituent effects of the methyl group of thymine: for the hydrogen-bond energy it is merely a geometric effect, while for the NMR parameters it is an electronic effect. The second example deals with the accuracy of geometries obtained with different basis sets for several DFT functionals, and the influence of core electrons and relativistic corrections on it. It will be shown that there are several DFT functionals that perform well, with average absolute deviations around or below 1.0 pm. [2, 3] Finally, we will report the application of Time-Dependent DFT (TD-DFT) using the LB94 functional for the computation of molecular polarizabilities for a set of organic molecules, as well as amino acid residues. [4] The polarizability is an intrinsic property of a molecule, and can be used in polarizable force fields for describing polarization effects within the chemical environment, for instance within QM/MM methods.

[1] M. Swart, C. Fonseca Guerra and F.M. Bickelhaupt, J. Am. Chem. Soc. 2004, 124, 16718
[2] M. Swart and J.G. Snijders, Theor. Chem. Acc. 2003, 110, 34
[3] M. Swart, A.W. Ehlers and K. Lammertsma, Mol. Phys. 2004, 102, 2467
[4] M. Swart, J.G. Snijders and P.Th. van Duijnen, J. Comp. Meth. Sci. Engin. 2004, 4, 419