POSITION 1: For students having a Masters or equivalent from outside
the European Union.

POSITION 2: For students having a Masters or equivalent from a European Union
country.

POSITION 1 : Development  of New Functionals and Algorithms for 
Time-Dependent Density-Functional Theory (TDDFT) and 
Implementation in Gaussian- and Wavelet-based Programs

Starting date: September 2008.

Funding: 3 year RTRA scholarship (approximately 1650 Euro gross per month.)

Background:  Since its introduction into Quantum Chemistry by one of us over 
a decade ago [C95], time-dependent density-functional theory (TDDFT) has 
become the dominant single-determinant method for modeling the excited 
states of medium and large molecules.  (See Ref. [C08] for notes from a 
recent course on TDDFT.)  As such it is the obvious method for modeling the 
spectroscopy of nanoscale systems where it has already been applied to 
calculate the optical absorption spectra of fullerenes [BAHK98] and 
nanotubes [MRRV03].  The continued success of this technique for treating 
the spectroscopy of nanoscale molecules ultimately depends both on 
(i) identifying and overcoming weaknesses of the method and (ii) the 
continued development of efficient algorithms and programs for carrying 
out calculations.  The objective of this thesis project is to do both, 
with the ultimate aim in mind of applying the improved method to studying 
molecular switches, excited states in biomolecules, and/or organic 
photovoltaic cells.

Research Project:  Problems with conventional TDDFT for photochemical 
modeling have been reviewed in Ref. [C01].  One which is particularly 
bothersome is the inadequate treatment of two-electron excitations which 
is needed if TDDFT is to be used for modeling photochemical reactions 
which pass through biradicalod intermediates.  It is proposed to pursue 
the method of polarization propagator corrections [C05] to gain insight 
into how new functionals can be constructed which go beyond the TDDFT 
adiabatic approximation to include explicit 2-electron excitations.  
This method is already partially implemented in the deMon2k program 
[deMon2k], so the first job is to complete and test that implementation.  
The familiarity gained from working with TDDFT in a Gaussian-based 
Quantum Chemistry code, will next be used to implement Casida's linear 
response TDDFT equations [C95] in a wavelet-based code [GDN+06] which 
will allow the application of TDDFT to significantly larger and more 
complex systems.

The ideal candidate will have completed his/her Masters in Quantum 
Chemistry, Theoretical Solid State Physics, or a related field.  He or 
she should be comfortable with formal methods and have experience in 
programming.  A condition of the scholarship is that the candidate must 
have a Masters degree (or the equivalent) from outside the European Union.   
The thesis can be written in English. However it seems normal that the 
student will want to learn French while living in France. 

References

[C08] Course on TDDFT at the level of 2nd Year Master's in Theoretical
Chemistry
http://dcm.ujf-grenoble.fr/PERSONNEL/CT/casida/Enseignement/M2/TDDFT/index.html

[GDN+06] L. Genovese, T. Deutsch, A. Neelov, S. Goedecker, and G. Beylkin,
J. Chem. Phys. 125, 074105 (2006).  Efficient solution of Poisson's equation
with free boundry conditons

[C05] M.E. Casida, J. Chem. Phys. 122, 054111 (2005).  "Propagator Corrections
to Adiabatic Time-Dependent Density-Functional Theory Linear Response Theory"

[MRRV03] A.G. Marinopoulos, L. Reining, A. Rubio, and N. Vast, Phys. Rev. 
Lett. 91, 046402 (2003). Optical and Loss Spectra of Carbon Nanotubes:
Depolarization Effects and Intertube Interactions

[C01] M.E. Casida, in Accurate Description of Low-Lying Molecular States 
and Potential Energy Surfaces, ACS Symposium Series 828, edited by 
Mark R. Hoffmann and Kenneth G. Dyall (ACS Press: Washington, D.C., 2002),
ISBN 0-8412-3792-1, (Proceedings of ACS Symposium, San Diego, Calif., 2001),
pp. 199-220.  "Jacob's ladder for time-dependent density-functional theory:
Some rungs on the way to photchemical heaven"  Preprint available for download
at
http://dcm.ujf-grenoble.fr/PERSONNEL/CT/casida/research/SanDiego.pdf

[BAHK98] R. Bauernschmitt, R. Ahlrichs, F.H. Hennrich, and M.M. Kappes, 
J. Am. Chem. Soc. 120, 5052 (1998).  Experiment versus Time Dependent Density
 Functional Theory Prediction of Fullerene Electronic Absorption

[C95] M.E. Casida, in Recent Advances in Density Functional Methods, 
Part I, edited by D.P. Chong (Singapore, World Scientific, 1995), p. 155.
"Time-dependent density-functional response theory for molecules"
Preprint available for download at 
http://dcm.ujf-grenoble.fr/PERSONNEL/CT/casida/research/chong.ps

[deMon2k] The deMon2k program is described at the website 
http://www.demon-software.com/public_html/index.html


POSITION 2 : Improvement of TDDFT modeling of the spectroscopy of 
nanosystems through better understanding of the space-time trade-off 
in the exchange-correlation functional

Project Description :
The understanding of electronic excited states of nanometer size systems 
is essential for the efficient development of molecular switches, 
photobiology, and organic photovoltaic cells, to name just a few 
examples.  The currently most popular methodes for studying electronic 
excited states are the Bethe-Salpeter equation (BSE) and time-dependent 
density-functional theory (TDDFT [MUN+06]) in solid-state physics and 
CASPT2 and TDDDFT in quantum chemistry.  Of these methods, the linear 
response formulation of TDDFT (sometimes called Casida's equations [C95]) 
is nominally the simplest and has become the single-determinant method of 
chose for modeling the excited states of large and cocmplex systems.  
Nevertheless certain problems remain [C01], in particular two notorious 
problems which complicate the application of TDDFT to some particularly 
important problems: underestimation of charge transfer excitations whose 
understanding is often important in photobiologie, photochemistry, and 
photovoltaics, annd the lack of an explicit description of excitations 
of more than one electron, whose understanding is essential for describing 
funnel regions in photochemical reactions.  The origin of these problems 
is in the approximate description of the TDDFT exchange-correlation 
potential whose exact properties are relatively little known beyond the 
adiabatic approximation.  To clarify the nature of the needed corrections 
to the xc functional it is proposed to use optimized effective potential 
techniques [C95, HCS02] in the context of the BSE to find the pole 
structure of the xc kernel in TDDFT [C05].  Given this structure, we will 
create model xc kernels and we will implement them in efficient programs 
for the above mentionned applications.

References :

[C95] M.E. Casida, in Recent Advances in Density Functional Methods,
Part I, edited by D.P. Chong (Singapore, World Scientific, 1995), p.
155. "Time-dependent density-functional response theory for molecules"

[C99] M.E. Casida, Phys. Rev. B 59, 4694 (1999). "Correlated optimized
effective potential treatment of the derivative discontinuity and of
the highest occupied Kohn-Sham eigenvalue: A Janak-type theorem for
the optimized effective potential method"

[C01] M.E. Casida, in Accurate Description of Low-Lying Molecular
States and Potential Energy Surfaces, ACS Symposium Series 828, edited
by Mark R. Hoffmann and Kenneth G. Dyall (ACS Press: Washington, D.C.,
2002), ISBN 0-8412-3792-1, (Proceedings of ACS Symposium, San Diego,
Calif., 2001), pp. 199-220. "Jacob's ladder for time-dependent
density-functional theory: Some rungs on the way to photchemical
heaven"

[HCS02] S. Hamel, M.E. Casida, and D.R. Salahub, J. Chem. Phys. 116,
8276 (2002). "Exchange-only optimized effective potential for
molecules from resolution-of-the-identity techniques: Comparison with
the local density approximation, with and without asymptotic
correction"

[C05] Mark E. Casida, J. Chem. Phys. 122, 054111 (2005). "Propagator
Corrections to Adiabatic Time-Dependent Density-Functional Theory
Linear Response Theory"

[MUN+06] Time-Dependent Density-Functional
Theory, edited by M.A.L. Marques, C. Ullrich, F. Nogueira, A. Rubio,
and E.K.U. Gross, Lecture Notes in Physics (Springer: Berlin, 2006)

Prerequisites :
A Masters in Theoretical Chemistry and/or Physics is desirable as is a 
knowledge of programming, but the most essential thing is an interest in 
the methods of quantum chemistry and physics.  We will use correlated 
electronic structure methods at the fronteer between quantum chemistry 
and solid-state physics: density-functional theory (DFT), time-dependent 
DFT (TDDFT), many-body theory, and CASSCF.  We will be lead to modify 
quantum chemistry, and notably, DFT programs to test our ideas.  The 
student will be part of national (GdR-DFT++) and European (ETSF) 
networks of theoreticians working on problems similar to those described 
above.

POSITION 1 : Co-directed by Thierry Deutsch and Mark E. Casida
Potential candidates are requested to send a letter of application, 
curriculum vitae, and recommendation letters to both

1) Mark E. Casida
Professeur
Laboratoire de Chimie Thorique
Dpartement de Chimie Molcularie (DCM, UMR CNRS/UJF 5250)
Institut de Chimie Molculaire de Grenoble (ICMG, FR2607)
Universit Joseph Fourier (Grenoble I)
F38041 Grenoble
FRANCE

Tel: +33.4.76.63.56.28 
e-mail: mark.casida^ujf-grenoble.fr
http://dcm.ujf-grenoble.fr/PERSONNEL/CT/casida/

Secretary: Sylvie POCHOLLE
Tel: +33.4.76.63.57.06
Fax: +33.4.76.51.42.67

2) Thierry DEUTSCH
Laboratoire de simulation atomique
Dpartement de Recherche Fondamentale sur la Matire condense (DRFMC/SP2M/L_Sim)
CEA-Grenoble

Tel: +33.4.38.78.34.06
e-mail: Thierry.Deutsch^cea.fr

Electronic applications are encouraged.  An acknowledgement will be 
sent upon receipt.

POSITION 2 : Directed by Mark E. Casida
Potential candidates are requested to send a letter of application, 
curriculum vitae, and recommendation letters to 
Mark E. Casida
Professeur
Laboratoire de Chimie Thorique
Dpartement de Chimie Molcularie (DCM, UMR CNRS/UJF 5250)
Institut de Chimie Molculaire de Grenoble (ICMG, FR2607)
Universit Joseph Fourier (Grenoble I)
F38041 Grenoble
FRANCE

Tel: +33.4.76.63.56.28 
e-mail: mark.casida^ujf-grenoble.fr
http://dcm.ujf-grenoble.fr/PERSONNEL/CT/casida/

Secretary: Sylvie POCHOLLE
Tel: +33.4.76.63.57.06
Fax: +33.4.76.51.42.67

Electronic applications are encouraged.  
An acknowledgement will be sent upon receipt.