Template Function sequant::detail::extended_wick

• Defined in File wick_extended.cpp

Function Documentation

template<Statistics S>
ExprPtr sequant::detail::extended_wick(ExprPtr input, const ExtendedWickOptions &opts, WickTheorem<S> &stats_sink)

applies the extended (generalized-normal-order) Wick theorem to input; this is WickTheorem::compute() under a MultiProduct vacuum

Parameters:

• input – a Product or Sum of Products with NormalOperator factors normal-ordered relative to Vacuum::MultiProduct, or an ExprPtr to a NormalOperatorSequence

• stats_sink – the WickTheorem whose stats() accumulate those of the standard theorem’s runs

Throws:

Exception – if an ordinal of opts.nop_connections or opts.nop_avoided_connections is not that of an input NormalOperator of a term with operators; a term without operators is kept as it is

Returns:

the result in which every γ, η and κ index is active; the core (virtual) part of a contraction is a Kronecker delta, applied unless both of its indices are external

Pre:

the default context’s vacuum is MultiProduct