Class DIISSubspace

java.lang.Object

org.episteme.natural.chemistry.computational.quantum.DIISSubspace

public class DIISSubspace
extends Object

Direct Inversion in the Iterative Subspace (DIIS) accelerator. Improves SCF convergence by minimizing the error vector in a subspace of previous iterations.

Since:

1.0

Author:

Silvere Martin-Michiellot, Gemini AI (Google DeepMind)

Constructor Summary

Constructors

Constructor	Description
DIISSubspace(int maxSubspaceSize)

Method Summary

Modifier and Type	Method	Description
void	add(Matrix<Real> F, Matrix<Real> error)	Adds an iteration to the subspace.
Matrix<Real>	extrapolate()	Extrapolates a new Fock matrix using the DIIS equations.

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

DIISSubspace

public DIISSubspace(int maxSubspaceSize)

Method Details

add

public void add(Matrix<Real> F,
 Matrix<Real> error)

Adds an iteration to the subspace.

Parameters:

F - The Fock matrix of the current iteration.

error - The error vector (usually FDS - SDF).

extrapolate

public Matrix<Real> extrapolate()

Extrapolates a new Fock matrix using the DIIS equations. Solve B * c = r for c. New F = sum(c_i * F_i).