Reference/API

E(p, q)

Constructs an expression containing a single excitation operator.

act_on_ket(::Operator)

All typed extending Operator must overload this function. It should return the expression you end up with after acting the operator on a normal RHF ket.

Example:

$E_{p q} |HF⟩ = (2 δ_{p q} C(p∈O,q∈O) + E_{p q} C(p∈V,q∈O)) |HF⟩$

delta(indices...)

Construct an expression consisting of a single Kronecker delta of the given indices.

disable_color()

Disables the coloring of MO-indices to indicate orbital space constraints globally. This will make all constraints be printed explicitly which can make some terms a bit long to read. Color is enabled by default.

disable_color(S)

Disables the coloring for a specific orbital space. This can be useful when dealing with a medium-large number of orbital spaces, and having distinguishable colors is infeasible.

disable_color_translated()

Disables the coloring of indices that has been translated.

disables_index_translation()

Disables the translation of summation indices over occupied and virtual to be printed as ijkl... and abcd... respectively instead of pqrs...

See enable_index_tranlation

e(p, q, r, s) = E(p, q) * E(r, s) - δ(r, q) * E(p, s)

Alias for the two electron singlet excitation operator. ```

enable_color()

Enables the coloring of MO-indices to indicate orbital space constraints. Color is enabled by default. The default coloring scheme is given by:

• GeneralOrbital: :nothing
• OccupiedOrbital: :light_green
• VirtualOrbital: :cyan

enable_color_translated()

Enables the coloring of indices that has been translated.

enable_index_translation()

Enables the translation of summation indices over occupied and virtual to be printed as ijkl... and abcd... respectively instead of pqrs...

By default translated indices lose their subspace coloring to reduce redundant information (unless the index is in an even stricter subspace which requires coloring nevertheless). To re-enable the coloring see enable_color_translated.

This is enabled by default.

Print term to numpy's einsum routine

Used with https://github.com/alexancp/einsumpath-to-eT to generate Fortran subroutines for eT.

printeTfunctiongenerator(name, ex, symbol, indices, translation, [wftype], [tensortranslation], [noinputtensors], [outperms])

printjuliafunction(name, ex, symbol, indices, translation, [tensortranslation], [explicittensor_blocks])

set_color(S, [color=default_color(S)])

Sets the color of a given orbital space to the specified color, or the default if none is given. Allowed colors are given by the Base.text_colors dict. This includes integers in the range 0-255 which the corresponding colors can be found in this table on Wikipedia.

δ(indices...)

Unicode alias for delta.

τ(p, q)

Constructs an expression containing a single triplet excitation operator.

GeneralOrbital

Top level supertype of all orbital spaces. Any orbital subspace is a subtype of this type.

OccupiedOrbital

Type representing all occupied orbitals.

VirtualOrbital

Type representing all virtual orbitals.