Our research focuses on (i) ab initio quantum theory of molecular electronic
structure, nuclei, and other many-body systems,
(ii) molecular properties and spectroscopy, (iii) reaction dynamics and mechanisms,
and (iv) theory of intermolecular forces. We design and apply sophisticated
quantum-mechanical methods that enable precise determination of potential
energy surfaces and property functions for both existing and hypothetical
molecular systems in their ground and excited states, calculations
of intermolecular potentials for van der Waals complexes, and studies of
nuclear structure.
We focus on new quantum many-body methods that include electron correlation,
particularly on the coupled-cluster theory and its highly original renormalized, extended,
multi-reference, equation-of-motion, and response variants developed by our group
that allow us to study bond breaking, radicals, biradicals, and other open-shell problems,
electronically excited states, electron-transfer processes,
molecular properties in vibrationally and electronically excited states, and transition
probability coefficients for various types of spectroscopy. We also develop local
correlation coupled-cluster methods, which can be applied to
large molecular systems with hundreds of non-dydrogen atoms and which
are characterized by the linear scaling of the
CPU time with the system size and coarse-grain parallelism, while preserving high accuracies
that coupled-cluster theories offer for smaller molecules. In addition to pure variants of
local coupled-cluster methods that utilize one particular approximation, we are
interested in the development of multi-level
extensions of local correlation approaches
that enable us to combine high-level methods based on coupled-cluster theory
with the low-order approaches, such as the second-order many-body perturbation theory,
without splitting molecular systems into ad
hoc fragments and saturating dangling bonds.
Our main interest is
in high accuracy methods and methods based on first principles of quantum
mechanics (no empirical parameters other than fundamental constants)
that allow us to be predictive. We develop computer codes
for the standard and new coupled-cluster methods which we distribute through
a popular electronic structure package
GAMESS.
We combine electronic structure calculations with other first principles
simulations, including accurate calculations of ro-vibrational and electronic
spectra of molecules and van der Waals complexes.
We apply our methods to reaction mechanisms
in organic and bioinorganic chemistry, and reactions relevant to combustion, catalysis,
and atmospheric studies.
We also study dynamics of photo-induced and other elementary reactions, and
molecular electronic spectra, of interest in various areas of chemistry.
Our new ab initio methods based on coupled-cluster wave function ansatz
can be applied to other many-fermion systems
(for example, we have applied them, with considerable success, to
atomic nuclei, introducing modern coupled-cluster approaches developed
earlier by us and others in the
context of quantum chemistry to nuclear physics). We also examine alternative approaches to
accurate calculations for many-fermion systems with pair-wise interactions,
including the use of two-body cluster expansions to represent the virtually
exact many-fermion states.
In our research, we use advanced mathematical and computational techniques and fundamental
laws of physics to evaluate properties of molecular and other many-fermion systems
that are of interest to Chemists, Chemical, Molecular, and Condensed Matters Physicists, and Nuclear Theorists.
Our calculations provide ongoing experiments with new insights and allow us
to study molecular systems in the absence of experiment.
For the complete list of Professor Piecuch's publications,
please click
here.
For the Chemistry Department's
brochure page describing Professor Piecuch's
research, please click
here.
For the more complete information about Professor Piecuch's
academic career and biography, please go
here.
According to the ISI Web of Knowledge,
as of December 15, 2011, the scientific articles authored or co-authored by Piotr Piecuch
and included in the ISI Web of Knowledge databases, excluding conference proceedings,
have received 6,294 citations (Hirsch's h-index = 46; 38.85 citations per paper).
Members of our group receive high-level training, which
includes a deep understanding of fundamental chemical and physical laws and sophisticated
mathematical and computational skills that can be used in natural sciences and outside science.
We offer a wide range of topics for everybody who wants to join us.
Many of our computations are performed on the powerful, multi-processor computer systems
at the
MSU High-Performance Computing Center and the departmental
Supercomputer Facility. Our group owns two powerful 32-CPU PowerEdge R910 systems from Dell, in
addition to a number of well-configured quad- and dual-core core Dell PCs
and Origin 2000 from SGI. Each of the two PowerEdge R910 systems from Dell is a
powerful, multi-processor computer server that contains, as major components, 32 cores,
arranged as four 8-core Intel Xeon X7560 2.26GHz processor boards, 256 GB RAM,
and 13 local disks of 300 GB each, arranged in RAID configurations to
increase the I/O performance. We are most grateful to the Chemical
Sciences, Geosciences and Biosciences Division, Office of Basic
Energy Sciences, Office of Science, U.S. Department of Energy, for providing
the necessary funds to purchase these systems.
Our research has been supported by the following agencies and programs:
Chemical
Sciences, Geosciences and Biosciences Division, Office of Basic
Energy Sciences, Office of Science,
U.S. Department of Energy (06/01/10 - 05/31/13;
for more information,
please click here).
The Air Force Office of Scientific Research (AFOSR) through Spectral Sciences, Inc.,
the Small Business Technology Transfer (STTR) Program,
05/03/10 - 02/02/11;
for more information,
please click here).
Chemical
Sciences, Geosciences and Biosciences Division, Office of Basic
Energy Sciences, Office of Science,
U.S. Department of Energy (06/01/07 - 05/31/10;
for more information,
please click here).
Chemical
Sciences, Geosciences and Biosciences Division, Office of Basic
Energy Sciences, Office of Science,
U.S. Department of Energy (09/01/04 - 05/31/07;
for more information,
please click here).
Japan Society for the Promotion of Science,
the JSPS Invitation Fellowship for Research in Japan
(10/01/05-11/30/05).
National Science Foundation, ITR Small Grants
(09/01/03--08/31/06; for more information
please click here).
The Alfred P. Sloan Research Foundation (09/16/02--09/15/04).
Office of Basic Energy Sciences, SciDAC Computational Chemistry Program,
U.S. Department of Energy (09/01/01 - 08/31/04;
for more information,
please click here).
National Science Foundation, CHE-Chemical Instrumentation (08/15/99 - 07/31/02;
for more information, please click
here).
MSU Intramural Research Grant Program, Science and Engineering Award (New Faculty;
05/15/99 - 09/15/00; for more information,
please click here).
We gratefully acknowledge this support.
We were also awarded the following grant (with three other co-PIs):
National Science Foundation, PHY-Nuclear Theory
(06/01/08--05/31/11; awarded in April 2008; for more information,
please click here).
Our group collaborates or has collaborated with many other researchers,
including, for example,
Professors Mark S. Gordon
from the Iowa State University and Ames Laboratory,
Stanislaw A. Kucharski from the University of Silesia,
David J. Dean
and
Thomas Papenbrock
from the Oak Ridge National Laboratory and University of Tennessee,
Morten Hjorth-Jensen
from the University of Oslo,
Robert Roth
from the Technical University in Darmstadt,
John C. Polanyi
from the University of Toronto,
Donald G. Truhlar and
Christopher J. Cramer
from the University
of Minnesota,
Antonio J.C. Varandas from the University of Coimbra,
Hiroshi Nakatsuji from the Quantum Chemistry Research Institute in Kyoto (previously
at Kyoto University),
Masahiro Ehara from the Institute of Molecular Science in Okazaki
(previously at Kyoto University),
Debashis Mukherjee from the Indian Association for the Cultivation of Science,
Karl F. Freed from
the University of Chicago,
Henry F. Schaefer III
and
Wesley D. Allen
from the University of Georgia,
Laura Gagliardi
from the University of Minnesota (previously, at the University of Geneva),
and
C. David Sherrill from Georgia Tech.
Our collaboration with Professor M.S.
Gordon and
Dr. Michael W. Schmidt
has focused on the incorporation of the coupled-cluster methods and programs
developed by the Piecuch group in the popular computational chemistry
structure software package
GAMESS, although we have also worked together on various application projects. Our collaboration
with Professors David J. Dean, Morten Hjorth-Jensen, Thomas Papenbrock, and, more recently,
Professor Robert Roth has focused on the
nuclear many-body problem. We also worked with
Professor Alex Brown from the National Superconducting Cyclotron Laboratory
at Michigan State University on calculations for heavier atomic nuclei.
You can contact either one of us or you can send us a message to Professor Piotr Piecuch's
secretary, Ms. Virgene Rector, by clicking here
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