Quantum chemical models#
In GQCP, a quantum chemical (wave function) model is defined to be a parametrization of a certain kind of wave function. To encapsulate the optimizable parameters related to a certain quantum chemical method, we currently provide the following models:
CCD
CCSD
CI
AP1roG
vAP1roG
RHF
UHF
CCD#
CCSD#
CI#
All of the configuration interaction wave functions are expressed using the wave function model LinearExpansion. Once obtained, you can calculate the associated one- and two-electron density matrices straightforwardly.
D = linear_expansion.calculate1DM()
d = linear_expansion.calculate2DM()
const auto D = linear_expansion.calculate1DM();
const auto d = linear_expansion.calculate2DM();
If the underlying ONV basis is spin-resolved, the C++ library also offers the alpha and beta components.
const auto D_spin_resolved = linear_expansion.calculateSpinResolved1DM();
const auto d_spin_resolved = linear_expansion.calculateSpinResolved2DM();