pydmqmc.utils.sc0

pydmqmc.utils.sc0(ba, sys)

Hamiltonian matrix element between a state and itself.

Parameters:

baarray_like

Bitarray for the state.

sysIntegral

System object with integral information.

Returns:

float

Hamiltonian matrix element.

See also

sc1, sc2

Other Slater-Condon rules.

pydmqmc.systems.Integral.generate_hamiltonian

Uses this function to generate the Hamiltonian matrix.

Notes

Math from Szabo and Ostlund (Table 2.5, Case 1) [1]:

\[<\Psi_{0}|H|\Psi_{0}> = \sum_{a} <a|h|a> + 1/2 \sum_{a,b} <ab|ab> - <ab|ba>\]

where \(a\) and \(b\) are occupied orbitals. Note that this equation is written in physicists’ notation.

References

[1]

Attila Szabo and Neil S. Ostlund, “Modern Quantum Chemistry: Introduction to Advanced Electronic Structure Theory,” Dover Books on Chemistry, 1996