Full Configuration Interaction

class pydmqmc.methods.FullConfigurationInteraction(system)

Bases: Analytic

Perform full configuration interaction (FCI) for a given Hamiltonian.

FCI is accomplished by performing exact diagonalization.

Attributes

energies	FCI energies.
ran_calculation	Whether or not the calculation has been run.
system	The System object to which this method is applied.
wavefunctions	FCI wavefunctions.

Methods

run()	Find the exact solution to the Schrodinger equation.
save_data(basename[, energy_filetype, ...])	Save the final energies and wavefunctions to file.

Warning

The supplied system must have a hermtian Hamiltonian.

run()

Find the exact solution to the Schrodinger equation.

Internally, uses numpy.linalg.eigh. The eigenvalues and eigenvectors are stored as the energies and wavefunctions attributes, respectively.

save_data(basename, energy_filetype='csv', wavefunction_filetype='csv', pickle_protocol=None)

Save the final energies and wavefunctions to file.

The basename and filetype parameters will be used to construct filenames for all of the data written to file. For example, if basename is “test_run” and the energy_ and wavefunction_filetype are both “csv”, the energies will be saved to “test_run_energies.csv” and the wavefunctions will be saved to “test_run_wavefunctions.csv”.

Parameters:

basenamestr

Base name used to construct the filenames for the energies and wavefunctions

energy_filetype, wavefunction_filetypestr, default “csv”

File type (aka extension) with which to save the energies. Supported types are:

• “csv” : comma-separated value file

• “npy” : NumPy binary file

• “pkl” : Python pickle file

• “txt” : text file (space-delimited)

pickle_protocolunt, optional

Protocol version to use if either filetype is “pkl”. If none, uses pickle’s default.

property energies

FCI energies.

property ran_calculation

Whether or not the calculation has been run.

property system

The System object to which this method is applied.

property wavefunctions

FCI wavefunctions.