ffsim.uccsd_generator_restricted

ffsim.uccsd_generator_restricted(t1, t2)[source]

Restricted unitary coupled cluster, singles and doubles (UCCSD) generator.

The restricted UCCSD generator is

\[T - T^\dagger\]

where \(T\) is the restricted CCSD generator (see ccsd_generator_restricted()).

Parameters:

  • t1 (ndarray) – The singles amplitudes tensor of shape (nocc, nvrt), where nocc is the number of occupied orbitals and nvrt is the number of virtual orbitals.

  • t2 (ndarray) – The doubles amplitudes tensor of shape (nocc, nocc, nvrt, nvrt), where nocc is the number of occupied orbitals and nvrt is the number of virtual orbitals.

Return type:

FermionOperator

Returns:

The UCCSD generator.