Difference between revisions of "Much more about QMC here"

From Qmcchem
Jump to navigation Jump to search
Line 6: Line 6:
 
</ul>
 
</ul>
  
In what follows a self-contained presentation of QMC is proposed. We shall concentrate on the T=0 QMC approaches defined in a continuous space since such conditions correspond to electronic structure theory.
+
In what follows a self-contained presentation of QMC is proposed. We shall concentrate on the T=0 QMC approaches defined in a continuous space corresponding to electronic structure theory conditions.
  
 
In order to make easier the presentation, we shall first consider the case of a one-dimensional system defined in a continuous space and no fermionic statistics. Second, we shall say a few words about the generalization to arbitrary number of dimensions (actually, 3N where N is the number of electrons). It is a nice aspect of Monte Carlo methods that such a generalization is easy and does not bring specific difficulties. Finally, we shall consider how to introduce the specific constraints due to the Pauli principle.  
 
In order to make easier the presentation, we shall first consider the case of a one-dimensional system defined in a continuous space and no fermionic statistics. Second, we shall say a few words about the generalization to arbitrary number of dimensions (actually, 3N where N is the number of electrons). It is a nice aspect of Monte Carlo methods that such a generalization is easy and does not bring specific difficulties. Finally, we shall consider how to introduce the specific constraints due to the Pauli principle.  
  
 
I. T=0 QMC for a continuous one-dimensional system with no specific symmetry constraints
 
I. T=0 QMC for a continuous one-dimensional system with no specific symmetry constraints

Revision as of 17:39, 24 October 2010

Quantum Monte Carlo methods are powerful probabilistic approaches for computing quantum averages of a N-body quantum system described by a Schrödinger equation. Many QMC variants known under various acronyms exist in the literature. We propose here to classify them as follows:

  • Zero-temperature (T=O) and Finite-temperature (T diff 0) QMC methods
  • QMC defined in continuous or discrete (lattice) configuration space
  • QMC for Boltzmanon, Fermion, or Boson particles.

In what follows a self-contained presentation of QMC is proposed. We shall concentrate on the T=0 QMC approaches defined in a continuous space corresponding to electronic structure theory conditions.

In order to make easier the presentation, we shall first consider the case of a one-dimensional system defined in a continuous space and no fermionic statistics. Second, we shall say a few words about the generalization to arbitrary number of dimensions (actually, 3N where N is the number of electrons). It is a nice aspect of Monte Carlo methods that such a generalization is easy and does not bring specific difficulties. Finally, we shall consider how to introduce the specific constraints due to the Pauli principle.

I. T=0 QMC for a continuous one-dimensional system with no specific symmetry constraints