SMMP - Stochastic Methods for Molecular Properties

Possible titles:

  1. Stochastic Methods for Molecular Properties (SMMP)
  2. Stochastic Methods for Chiroptical Properties (SMCP or ChiroStoch)

  3. Deterministic methods need large Hilbert spaces for effective expansions of the many-electron wave function This is however largely redundant (Ivanic 2001)

  4. Stochastic algorithms are highly parallelizable in the number of walkers. I will develop my skills in parallel programming techniques by developing this project.

Research questions:

  • Understanding chiroptical properties for large chemical systems

Objectives of the project:

  • The calculation of molecular properties with high accuracy and for systems of relevant size

    1. High accuracy means coupled cluster (CC) wave functions
    2. Systems for which CC is an option are limited by its polynomial scaling
    3. It is possible to reduce the scaling, e.g. by means of local approaches to the electron correlation problem, but this has been proven to not be as effective for molecular properties as for energies
  • Devise the appropriate stochastic approach to the solution of response equations

    1. We want the stochastic approach because it's (supposedly) embarassingly parallel. This can enable the study of the response properties for larger systems and provide benchmark results for lower level calculations.
    2. Low scaling (or better parallelization options) + (perhaps?) controllable error of stochastic methods are the key advantages. Find relevant literature on both! (Booth 2014), (Coccia 2012)
  • The creation of the appropriate software toolbox with good scalability.

    1. The toolbox will be freely available under the appropriate open source license (GPL most likely!)

General background on quantum chemistry:

State of the art:

Problems to address:

  • The fermion sign problem. How do FCIQMC and CCMC avoid it? The sign problem is NP-hard (Troyer 2005) thus not solvable in polynomial time


  • Size of the systems investigated by stochastic methods in Fock space?
  • Properties by stochastic methods? VMC/DMC/FCIQMC?
  • Local correlation approaches for molecular properties?
  • L. Guidoni might have published some FCIQMC calculations on large molecular systems.


  1. Joseph Ivanic, Klaus Ruedenberg. Identification of deadwood in configuration spaces through general direct configuration interaction. Theor Chem Acc 106, 339–351 (2001). Link

  2. George H. Booth, Simon D. Smart, Ali Alavi. Linear-scaling and parallelisable algorithms for stochastic quantum chemistry. Molecular Physics 112, 1855–1869 (2014). Link

  3. Emanuele Coccia, Olga Chernomor, Matteo Barborini, Sandro Sorella, Leonardo Guidoni. Molecular Electrical Properties from Quantum Monte Carlo Calculations: Application to Ethyne. J. Chem. Theory Comput. 8, 1952–1962 (2012). Link

  4. C. David Sherrill. Frontiers in electronic structure theory. The Journal of Chemical Physics 132, 110902 (2010). Link

  5. Timothy J. Lee, Gustavo E. Scuseria. Achieving Chemical Accuracy with Coupled-Cluster Theory. 47–108 (1995). Link

  6. Trygve Helgaker, Torgeir A. Ruden, Poul J, Jeppe Olsen, Wim Klopper. Apriori calculation of molecular properties to chemical accuracy. Journal of Physical Organic Chemistry 17, 913–933 (2004). Link

  7. Attila Tajti, Peter G. Szalay, Attila G. Csaśzaŕ, Mihaĺy Kaĺlay, Jürgen Gauss, Edward F. Valeev, Bradley A. Flowers, Juana Vaźquez, John F. Stanton. HEAT: High accuracy extrapolated ab initio thermochemistry. The Journal of Chemical Physics 121, 11599 (2004). Link

  8. Trygve Helgaker, Poul J, Jeppe Olsen. Molecular Electronic-Structure Theory. (2000). Link

  9. W. A. Goddard. Theoretical Chemistry Comes Alive: Full Partner with Experiment. Science 227, 917–923 (1985). Link

  10. MatúDubecký, Lubos Mitas, Petr Jure. Noncovalent Interactions by Quantum Monte Carlo. Chemical Reviews (2016). Link

  11. Julien Toulouse, Roland Assaraf, Cyrus J. Umrigar. Introduction to the Variational and Diffusion Monte Carlo Methods. 285–314 (2016). Link

  12. Brian M. Austin, Dmitry Yu. Zubarev, William A. Lester. Quantum Monte Carlo and Related Approaches. Chemical Reviews 112, 263–288 (2012). Link

  13. R J Needs, M D Towler, N D Drummond, P López R'. Continuum variational and diffusion quantum Monte Carlo calculations. Journal of Physics: Condensed Matter 22, 023201 (2009). Link

  14. Roland Assaraf, Michel Caffarel, Anatole Khelif. The fermion Monte Carlo revisited. Journal of Physics A: Mathematical and Theoretical 40, 1181–1214 (2007). Link

  15. M. D. Towler. The quantum Monte Carlo method. physica status solidi (b) 243, 2573–2598 (2006). Link

  16. W. M. C. Foulkes, L. Mitas, R. J. Needs, G. Rajagopal. Quantum Monte Carlo simulations of solids. Reviews of Modern Physics 73, 33–83 (2001). Link

  17. G. C. Wick. Properties of Bethe-Salpeter Wave Functions. Phys. Rev. 96, 1124–1134 (1954). Link

  18. Alex J. W. Thom. Stochastic Coupled Cluster Theory. Phys. Rev. Lett. 105 (2010).