Research Kris Van Alsenoy

Abstract

This is a fundamental research project financed by the Research Foundation - Flanders (FWO). The project was subsidized after selection by the FWO-expert panel.

Researcher(s)

• Promoter: Van Alsenoy Kris
• Fellow: Krishtal Alisa

Research team(s)

Project type(s)

• Research Project

Abstract

Conjugated organic and organometallic compounds and their stable radicals, useful as organic semiconductors, will be synthesized and characterized using advanced pulse and multi-frequency EPR techniques. The combination with all-electron DFT quantum chemical calculations is essential to extract all available structural information contained in the spectroscopic data.

Researcher(s)

• Promoter: Van Alsenoy Kris
• Co-promoter: Blockhuys Frank
• Co-promoter: Goovaerts Etienne
• Co-promoter: Van Doorslaer Sabine

Research team(s)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Van Alsenoy Kris

Research team(s)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Van Alsenoy Kris

Research team(s)

Project type(s)

• Research Project

Abstract

The determination of the structure of biomolecules is an important aspect of biochemical sciences. Indeed, the molecular three dimensional structure has a determining influence on the molecule's chemical properties such as its reactivity. The main technique for the determination of the structure of biomolecules is single-crystal X-ray diffraction. The obtained molecular structure may therefore differ from the structure in solution, which is its active structure in the watery environment in the cell. Recent developments in NMR spectroscopy, such as Fourier transformation methods and pulse-techniques, make this technique particularly suitable for the determination of conformations of biomolecules in solution, thereby allowing even to study molecules which won't crystalise properly. Extracting structural information from NMR spectra is however not a trivial process. The relation between conformation and NMR parameters such as chemical shifts and coupling constants is up till now only determined by empirical rules. This is a consequence of the large number of factors influencing these properties, such as the influence of the nearby environment and the long range substituent effects on the chemical shifts, as well as the influence of conformational effects on the coupling constants. Furthermore, different experimental techniques must be employed to determine all the chemical shifts and coupling constants for the different atomic species in an accurate manner. Interpretation of NMR spectra can be strongly simplified by calculating the chemical shifts and coupling constants, with their different contributions, by quantum chemical methods. This allows moreover to acquire insight in the relationship between spectra and structure. Calculation of the chemical shifts and coupling constants allows a straightforward assignment and the different contributions to these quantities can be determined separately. This is a great advantage in atypical situations which cannot be compared with existing data, such as sterical hindrance or presence of relatively rare chemical elements. NMR spectra of different chemical elements, that are not being commonly measured, can be acquired without having to resolve to special experimental techniques.

Researcher(s)

• Promoter: Van Alsenoy Kris

Research team(s)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Cuyt Annie
• Co-promoter: Daelemans Walter
• Co-promoter: De Schutter Erik
• Co-promoter: Peeters Francois
• Co-promoter: Van Alsenoy Kris
• Co-promoter: Van Broeckhoven Christine

Research team(s)

Project type(s)

• Research Project

Abstract

Based on ab-initio calculations of increasing accuracy and with different models for the exchange-correlation functionals insight will be gained into the mechanism of the polarisation of a protein-water system, in particular the intra-molecular charge transfer. The obtained results will be modelled using multipolar models which are simple enough to allow their use in dynamical simulations of the protein-water complexes at finite temperatures.

Researcher(s)

• Promoter: Van Alsenoy Kris
• Fellow: Yang Mingli

Research team(s)

Project type(s)

• Research Project

Abstract

Implementation and optimalisation on linux pc's of the parallel software package BRABO for ab-initio calculations on many-electron systems. Methodologies used comprise wave-function based as well as methods based on Density Functional Theory.

Researcher(s)

• Promoter: Van Alsenoy Kris

Research team(s)

Project type(s)

• Research Project

Abstract

A hybrid QM/MM method will be implemented by connecting the QM program BRABO with the MM program CHARMM. Then a Link Atom method will be implemented to be able to split up a molecular system into a QM and a MM component if covalent bonds are broken during the process. Finally polarization terms will be added to the MM force field. Hence the QM component can be further reduced and a molecular dynamics simulation can be performed.

Researcher(s)

• Promoter: Van Alsenoy Kris
• Fellow: Swerts Ben

Research team(s)

Project type(s)

• Research Project

Abstract

In this project three novel classes of materials for conductometric gas sensors of which quantum chemical calculations have indicated favourable qualities, such as high stability and good manufacturing properties,will be synthesised and tested in practice. It concerns materials based upon : i)2,6-diphenyl-1,5-diaza-1,5-dihydro-s-indaceen ii)arylenevinylene trimers with N-methylpyrrole as the central ring iii)phenylene-nickel(II) complexes Several synthetic approaches will be investigated for each of these groups of compounds.

Researcher(s)

• Promoter: Van Alsenoy Kris
• Fellow: Vande Velde Christophe

Research team(s)

Project type(s)

• Research Project

Abstract

The Schrödinger equation, which giving quantum chemical information on systems, cannot be solved exactly for molecules. A frequently used approximation is the Hartree-Fock method, which can be used in a very efficient way in combination with the multiplicative integral approach (MIA), developed in the Antwerp research group. At this level however, the `correlation energy' is not taken into account. The DFT-method is a method that solves this problem, at a reasonable computational cost. The MIA forces are not implemented at this moment. Forces are necessary for the calculation of geometries and properties of molecules. The development of the MIA force method, the optimization of the DFT force code and the development of a DFT/MIA force method, are the aim of this project. The methods will be applied in the fields of materials science and pharmaceutical research.

Researcher(s)

• Promoter: Van Alsenoy Kris
• Fellow: Van Droogenbroeck Joris

Research team(s)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Lamoen Dirk
• Promoter: Van Alsenoy Kris
• Fellow: March Norman H.

Research team(s)

Project type(s)

• Research Project

Abstract

Aiming at new luminescent materials for Organic LEDs emitting in the blue, a number of graftcopolymers will be synthesized and their performances compared with those of blends of luminescent oligomers in a polymer matrix. The graftcopolymers will consist of derivatives of 1,4-bis?2,2-diphenylethenyl?benzene as the chromophores grafted in various percentages onto either a copolymer of vinylbenzylchloride (VBC) and vinylcarbazole or onto a copolymer of VBC and styrene.

Researcher(s)

• Promoter: Geise Herman
• Promoter: Van Alsenoy Kris
• Fellow: Wuyts Cindy

Research team(s)

Project type(s)

• Research Project

Abstract

With an emphasis on LEDs, sensors and solar cells, the project has two aims : (i) to design and synthesize novel, advanced organic materials guided by theoretical (ab-initio HF and/or DFT) calculations and (ii) to construct and test improved highly efficient, long lived devices with the help of nanocomposite technology.

Researcher(s)

• Promoter: Geise Herman
• Promoter: Van Alsenoy Kris

Research team(s)

Project type(s)

• Research Project

Abstract

Apart from exchange of researchers and information, the project aims at the synthesis of novel organic compounds : (i) calix[n]pyrroles, arylboronic acids, dendrimers (KUL) and (ii) conjugated oligomers and polymers comprising vinylthiophenes, vinylaryl units and their acetylene analogs (UIA). The compounds will be tested in modified membranes for recognition of neutral and ionic species (Poland, PAN).

Researcher(s)

• Promoter: Geise Herman
• Promoter: Van Alsenoy Kris

Research team(s)

Project type(s)

• Research Project

Abstract

Within this project theory and experiment will be combined in a study phosphorous compounds and their organometallic complexes. Theoretical calculations will be performed using state-of-the-art MO techniques such as QCI, CC, CASPT2 but also DFT-based calculations using recently developed exchange-correlation potentials. Experimental studies (vibrational IR and NMR) will be perfomed on these compounds and the results will be interpreted based on theoretical models derived from the calculations.

Researcher(s)

• Promoter: Van Alsenoy Kris

Research team(s)

Project type(s)

• Research Project

Abstract

In this project a number of topics will be studied. DFT will be extended towards the description of excited states and perfectly N-representable density matrices. In order to contribute to the understanding of optical properties of semiconductor systems, correlation effects on exitons and spin transport in heterostuctures will be studied. The influence of magnetic effects on clusters of 3d transition metal atoms will shed light on long-range coulomb behaviour. In an assessment of the performance of certain DFT functionals a number of calculations on molecules and clusters of interest to the farmaceutical industry as well as the nano-technology sector will be performed.

Researcher(s)

• Promoter: Van Alsenoy Kris

Research team(s)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Van Alsenoy Kris
• Fellow: Peeters Anik

Research team(s)

Project type(s)

• Research Project

Abstract

The project endeavours to provide theoretical support to the experimental research on gas sensors and an electronic nose based on electrically conducting oligomers, which will enable the experimental work to be carried out in a more efficient way. More to the point, this means that a deeper understanding will be sought of the collection of conditions a given oligomer must fulfil to be applied in a gas sensor: these conditions are the stability, ability to be deposited and sensitivity towards molecules in the vapour, of the doped material.

Researcher(s)

• Promoter: Van Alsenoy Kris
• Fellow: Blockhuys Frank

Research team(s)

Project type(s)

• Research Project

Abstract

It is the purpose of this project to unify a number of theoretical methods and techniques from different fields (quantum chemistry, condensed matter physics and statistical physics) related to molecules and materials into a coherent software package allowing to tackle a wide variety of problems of interest to the industry.

Researcher(s)

• Promoter: Van Alsenoy Kris

Research team(s)

Project type(s)

• Research Project

Abstract

The bilateral cooperation between the Institute of Photographic Chemistry, Chinese Academy of Science on the one hand and IMEC (Leuven) and Structural Chemsitry (UIA, Univ. Antwerpen) on the other hand has the following objectives: 1. Synthesis of new charge-transporting and light-emitting materials out of the group of arylenevinylenes and metal chelates 2. Evaluation of the new materials in OLED's and Solar Cells 3. Design of procedures to build and test new as well as existing organic semiconducting materials for use in field-effect transistors

Researcher(s)

• Promoter: Van Alsenoy Kris

Research team(s)

Project type(s)

• Research Project

Abstract

New (ab-initio) methods bases on the MIA-approach are developed. These methods are applied either in the study of molecules of biochemical or pharmaceutical interest such as neuroleptica, steroids and small peptides or in the study of molecules in the crystal phase.

Researcher(s)

• Promoter: Van Alsenoy Kris
• Fellow: Van Alsenoy Kris

Research team(s)

Project type(s)

• Research Project

Abstract

A hybrid QM/MM method will be implemented by connecting the QM program BRABO with the MM program CHARMM. Then a Link Atom method will be implemented to be able to split up a molecular system into a QM and a MM component if covalent bonds are broken during the process. Finally polarization terms will be added to the MM force field. Hence the QM component can be further reduced and a molecular dynamics simulation can be performed.

Researcher(s)

• Promoter: Van Alsenoy Kris
• Fellow: Swerts Ben

Research team(s)

Project type(s)

• Research Project

Abstract

The Schrödinger equation, which gives quantum chemical information on systems, cannot be solved exactly for molecules. A frequently used approximation is the Hartree-Fock method, which can be used in a very efficient way in combination with the multiplicative integral approach (MIA), developed in this research group. At this level however, the `correlation energy' is not taken into account. The HFCC-method is a method that solves this problem. Neither in the MIA nor in the HFCC method forces can be calculated at this moment. Forces are necessary for the calculation of geometries and properties of molecules. The development of the MIA-forces, the HFCC-forces and a combination of these methods, the HFCC/MIA method, are the aim of this project.

Researcher(s)

• Promoter: Van Alsenoy Kris
• Fellow: Van Droogenbroeck Joris

Research team(s)

Project type(s)

• Research Project

Abstract

The aim is to produce and characterize arylenevinylene compounds (AV-compounds) applicable in inter alia Organic Light Emitting Devices (OLED) and conductimetric gas sensors (Electronic Nose, EN). Objectives are: (i) Application of theoretical methods in the design and optimalisation of chemical structures and synthetic routes. (ii) Synthesis of new oligomers and polymers of high purity; optimalisation of synthetic routes and purification procedures. (iii)Determination and improvement of electronic properties.

Researcher(s)

• Promoter: Van Alsenoy Kris
• Co-promoter: Geise Herman

Research team(s)

Project type(s)

• Research Project

Abstract

Geometry optimisations based upon analytic gradient use a Newton-Raphson procedure which, in an iterative way, generate, given a geometry and gradients , a 'new'/'better' geometry. The evaluation of analytic gradients in each step of this iterative procedure is a very computational intensive step for large molecules. Based upon experience we learned that in large molecules, atoms in certain regions of a molecule refine faster than atoms in others. For the atoms in these 'refined' regions it not neccesary to re-evaluate forces on the atoms. A procedure based upon the expression : F(n) - F(n-1) = P(n) ( I(n)-I(n-1)) + (P(n) ' P(n-1)) I(n-1) in which F(m), P(m) and I(m) respectively stand for the forces, density and integrals in the m-th iteration, has been worked out to update the forces on the atoms in an iterative procedure.

Researcher(s)

• Promoter: Van Alsenoy Kris
• Fellow: Perez-Juste Ignacio

Research team(s)

Project type(s)

• Research Project

Abstract

State-of-the-art quantumchemical methode will be used in a study of the structure and electronic properties of low coordinated phosphorous compounds.

Researcher(s)

• Promoter: Van Alsenoy Kris

Research team(s)

Project type(s)

• Research Project

Abstract

Density Functional Theory (DFT) has been well established for a long time, and within the framework of the Local Density Approximation (LDA) it has been successfully applied to atoms, molecules, solide (2D as well as 3D), surfaces, polymers, etc. Up till now deficiencies within this approximation can be reduced by the use of Gradient Corrected functionals (GGA) which seem to have a sizeable effect on molecules, less in solide, while in polymers it still remains to be investigated. Other means of improvement of the LDA are the Optimized Effective Potential (OEP), Many Body Perturbation methode (MBPT), density functionals for excited states, nonlocal density functionals based on pair-correlation functionals and Wigner-functions have recently been developed, but have only been applied to relatively simple systems. Despite the need for further improvements LDA is still an outstanding tool to investigate the properties of complex systems and the mechanism of physical phenomena. The different teams involved in the present project have complementary background (chemistry, physics) and are working on complementary systems (atoms, molecules, polymers, semiconductors, biopolymers) using the DFT teelmique.The present proposal aims to extend the existing collaboration and the complementarity in knowledge will be important to realize the present study.

Researcher(s)

• Promoter: Van Alsenoy Kris

Research team(s)

Project type(s)

• Research Project

Abstract

The elastic properties of industrial polymers such as the nylons 11, 12 and 66 will be calculated. The Young's modulus as well as all other elastic constants are related to the second derivative of the total energy with repect to the force applied to the material. The energy of the ground stae will be calculated using and LDA functional (Kohn-Sham for exchange and Ceperly-Alder for correlation).

Researcher(s)

• Promoter: Van Alsenoy Kris

Research team(s)

Project type(s)

• Research Project

Abstract

New methods and algorithms will be developed to predict the structure of'proteins with a known amino acid sequence. In the first part of the investigation the secondary structure will be determined by quantum chemical calculations on the oligomer building blocks of' the protein. Next, neural networks will be used to determine the tertiary structure. After establishing a potential hypersurface for the active site, the time averaged effective conformation can be determined.

Researcher(s)

• Promoter: Van Alsenoy Kris
• Fellow: Peeters Anik

Research team(s)

Project type(s)

• Research Project

Abstract

The main objective of this project is to develop and implement a method which combines the DFT method and the MIA method. The MIA method is a computational procedure allowing ab-initio SCF studies on very large systems. The DFT/MIA method will allow accurate calculations on large systems including the effects of electron correlation in an efficient way.

Researcher(s)

• Promoter: Van Alsenoy Kris
• Fellow: Rousseau Bart

Research team(s)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Van Alsenoy Kris

Research team(s)

Project type(s)

• Research Project

Abstract

Interdisciplinarity (chemistry - physics - computer science) and complementarity (fundamental/applied aspects - substrates molecules/solids) are the key issues in the cooperation between seven Flemish research groups: Antwerp (Van Alsenoy, Lamoen), Leuven (Ceulemans, Schoonheydt), Ghent (Waroquier, Bultinck) and Brussels (Geerlings).

Researcher(s)

• Promoter: Van Alsenoy Kris

Research team(s)

Project type(s)

• Research Project

Abstract

The main objective of this project is to develop and implement a method which combines the DFT method and the MIA method. The MIA method is a computational procedure allowing ab-initio SCF studies on very large systems. The DFT/MIA method will allow accurate calculations on large systems including the effects of electron correlation in an efficient way.

Researcher(s)

• Promoter: Van Alsenoy Kris
• Fellow: Rousseau Bart

Research team(s)

Project type(s)

• Research Project

Abstract

Density Functional Theory (DFT) will be used for the calculation of structural, mechanical and electronic properties of solids, polymers and bio-polymers. Improvement of the local density approximation by means of exponentially or gaussian screened functionals will be investigated. The Multiplicative Integral Approximation (MIA) will be used to improve computational efficiency and different non-local DFT methods will be calibrated for model systems through their comparison with accurate ab-initio methods.

Researcher(s)

• Promoter: Van Alsenoy Kris
• Co-promoter: Geise Herman
• Co-promoter: Martin Jan

Research team(s)

Project type(s)

• Research Project

Abstract

New (ab-initio) methods bases on the MIA-approach are developed. These methods are applied either in the study of molecules of biochemical or pharmaceutical interest such as neuroleptica, steroids and small peptides or in the study of molecules in the crystal phase.

Researcher(s)

• Promoter: Van Alsenoy Kris
• Fellow: Van Alsenoy Kris

Research team(s)

Project type(s)

• Research Project

Abstract

Use of the combined MIA and direct-SCF approach for the development of software allowing ab-initio calculations on large systems of interest to biochemistry and pharmacology.

Researcher(s)

• Promoter: Van Alsenoy Kris

Research team(s)

Project type(s)

• Research Project

Abstract

Recent improvements in quantum theory of materials admit simulations and design of new materials. In this respect the 'density functional' theory is used, esp. the 'local density approximation'. in which the total energy of the system is expressed in terms of the electron density function. In this project this method is applied to (bio)polymers.

Researcher(s)

• Promoter: Van Doren Victor
• Co-promoter: Van Alsenoy Kris

Research team(s)

Project type(s)

• Research Project

Abstract

Use of existing software and development of new software for the calculation of electronic and mecha nical properties of large systems using Density Functional Theory. The effect of new non-local densi ty functionals (generalised gradient expansion, exponential or gaussian-screened density functionals) upon the calculated quantities will be studied in particular.

Researcher(s)

• Promoter: Van Alsenoy Kris

Research team(s)

Project type(s)

• Research Project

Abstract

Use of a combined MIA-and direct MP2 approach for the development of software allowing MP2 calculations in the study of dynamic properties of molecules in molecular crystals.

Researcher(s)

• Promoter: Van Alsenoy Kris
• Fellow: Peeters Anik

Research team(s)

Project type(s)

• Research Project

Abstract

Use of the combined MIA and direct SCF approach for the development of software allowing ab-initio calculations on large systems of interest to biochemistry and pharmacology.

Researcher(s)

• Promoter: Van Alsenoy Kris

Research team(s)

Project type(s)

• Research Project

Abstract

The multiplicative integral approximation which has proven its usefullness for the evaluation of molecular wavefunctions at the SCF level for large systems, will be applied for the evaluation of the energy contributions due to electron correlation at the MP2 level.

Researcher(s)

• Promoter: Van Alsenoy Kris
• Fellow: Franckaerts Katrien J M

Research team(s)

Project type(s)

• Research Project

Abstract

To make ab initio calculations on large, biologically interesting molecules possible, one needs supercomputers and special methods. The multiplicative integral approximation, originally used to fasten the self-consistent field procedure, will now be applied in the evaluation of the forces on nuclei.

Researcher(s)

• Promoter: Van Alsenoy Kris
• Fellow: Peeters Anik

Research team(s)

Project type(s)

• Research Project

Abstract

The multiplicative integral approximation which has proven its usefullness for the evaluation of molecular wavefunctions at the SCF level for large systems, will be applied for the evaluation of the energy contributions due to electron correlation at the MP2 level.

Researcher(s)

• Promoter: Van Alsenoy Kris
• Fellow: Franckaerts Katrien J M

Research team(s)

Project type(s)

• Research Project

Abstract

New (ab-initio) methods based on the MIA-approach are developed. These methods are applied either in the study of molecules of biochemical or pharmaceutical interest such as neuroleptica, steroids and small peptides or in the study of molecules in the crystal phase.

Researcher(s)

• Promoter: Geise Herman
• Fellow: Van Alsenoy Kris

Research team(s)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Van Alsenoy Kris

Research team(s)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Van Alsenoy Kris

Research team(s)

Project type(s)

• Research Project

Abstract

To make ab initio calculations on large, biologically interesting molecules possible, one needs supercomputers and special methods. The multiplicative integral approximation originally used to fasten the self-consistent field procedure, will now be applied in the evaluation of the forces on nuclei

Researcher(s)

• Promoter: Van Alsenoy Kris
• Fellow: Peeters Anik

Research team(s)

Project type(s)

• Research Project

Abstract

Development of methods allowing the study of large molecules (of interest to biochemistry) using ab-initio gradient techniques

Researcher(s)

• Promoter: Van Alsenoy Kris

Research team(s)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Van Alsenoy Kris

Research team(s)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Geise Herman
• Fellow: Van Alsenoy Kris

Research team(s)

Project type(s)

• Research Project