Function sequant::mbpt::op::ref_av

• Defined in File vac_av.cpp

Function Documentation

ExprPtr sequant::mbpt::op::ref_av(ExprPtr expr, EVOptions<std::wstring> opts = {})

computes the reference expectation value

See also

EVOptions

Note

equivalent to vac_av if the reference state is the Wick vacuum, i.e. if get_default_context().index_basis_registry()->reference_occupied_space() == get_default_context().index_basis_registry()->vacuum_occupied_space()

Note

Connectivity constraints are empty by default.

Parameters:

• expr – [in] input expression

• opts – [in] controls the behavior,

Pre:

When the reference differs from the Wick vacuum and the vacuum is not MultiProduct, opts.connect and opts.do_not_connect must both be empty.