National Nanotechnology Infrastructure Network

National Nanotechnology Infrastructure Network

Serving Nanoscale Science, Engineering & Technology



Pseudopotential Algorithms for Real Space Energy Calculations


The PARSEC package provides users with the ability to solve the electronic structure of confined systems such as atomic clusters, molecules, and quantum dots by using a real space approach. The current version can calculate forces and is capable of performing ab-initio molecular dynamics studies, including simulated annealing.

The code takes advantage of three common approximations to perform electronic structure calculations. These include the Born-Oppenheimer approximation (seperation of nuclear and electronic degrees of freedom), pseudopotentials, and local density or generalized gradient approximations for exchange and correlation effects.

PARSEC solves the Kohn-Sham equation on a cubic grid in real space and is ideally suited for situations where approaches that rely on periodic boundary conditions (i.e. plane-waves, LMTO) can fail. The real space approach is particularly important in low dimensional systems such as atomic clusters, molecules, finite nanowires, and quantum dots.

A MATLAB version that can run on a laptop is now available by request from the developers.


  • Electronic structure of Low Dimension Structures (Quantum Dots, Clusters, Molecules)
  • Optical Absorption and Spectra
  • Charged Systems
  • Time Dependent Density Functional Theory - Molecular Dynamics
  • Structural Relaxations
  • Electronic Transport


  J. R. Chelikowsky, Y. Saad, M. Troullier, A. Stathopoulos, K. Wu, S. Ogut, H. Kim, M. Jain, I. Vasilev, L. Kronik, R. Burdick, A. Makmal, M. Alemany, M. Tiago, C. Pickard, J. Nocedal, J. L. Martins, and K. Burke (for specific contributions see this page)

 Much of the work on this program was done at the University of Minnesota with subsequent contributions from the Weizmann Institute and the Institute for Computational Engineering and Sciences (ICES) at the University of Texas.

Getting Started:

PARSEC Website (contains source code, documentation, and much more!)
User Guide for Version 1.1

Lectures and Tutorials from the 2006 CNF Fall Workshop "Building Nanostructures Bit by Bit"

     "Real space approaches for modeling clusters, nanowires, and more (pdf)", (Murilo Tiago, University of Texas)

                                                                                                                      [Video of talk on CNF MediaSite]

     Parsec Tutorial by Murilo Tiago (pdf version) (html


Running PARSEC using NNIN resources
Contact Derek Stewart stewart (at) or Michael Stopa, stopa (at)

Relevant Research Articles:

The First Article 

Overview Papers
Recent Applications and Developments...

Questions, Comments...

Please contact:

Derek Stewart
stewart (at)
Cornell Nanoscale Science and Technology Facility, Cornell University