td
Timedependent linear response theory for excited states. This command can appear in the global context.
Subcommands
Options
cis

Flag for whether the excited states are computed from Configutation Interaction Singles (CIS) or TammDancoff Approximation (TDA).
 The type is bool
 The default is false
 The value must be one of:
true
 Do CIS/TDA for excited states.false
 Do RandomPhase Approximation (RPA)/TimeDependent Density Functional Theory (TDDFT) for excited states.
convergence

Convergence threshold for the iterative subspace solver, tested on on the infinity norm of the residual vectors.
 The type is real
 The default is 1e6
 The value must be positive
frozen_core

Whether to use frozencore approximation.
 The type is bool
 The default is false
incore

Flag for whether to construct the response matrix explicitly.
 The type is bool
 The default is false
 The value must be one of:
true
 Construct the response matrix explicitly and store it in memory. This option is only available for response calculations based on a HartreeFock wavefunction, and should be used only for testing purposes.false
 Do not construct the response matrix explicitly, but compute the matrixvector product instead. This will require iterative solvers.
linear_dependency_threshold

Threshold for removing linearly dependent vectors based on the square of singular values of the matrix.
 The type is real
 The default is 1e10
 The value must be positive
load_transition_density

Load the AO transition density matrix from file (in arma::arma_binary) format.
 The type is string
 There is no default value.
max_iter

Maximum number of iterations for the iterative subspace solver.
 The type is int
 The default is 128
 The value must be positive
min_excitation_energy

Only calculate excited states with excitation energy (in eV) greater than the specified value.
 The type is real
 There is no default value.
 The value must be nonnegative
n_states

Number of excited states to be calculated.
 The type is int
 The default is 3
 The value must be nonnegative
name

Specify the name of a set of results.
This option is deprecated.
 The type is string
 There is no default value.
orthonormal_threshold

Threshold for orthonormalization of the suspace vectors.
 The type is real
 The default is 1e10
 The value must be positive
print_level

Print level.
 The type is int
 There is no default value.
 The value must be one of:
2
 No output1
 Minimum output0
 Output that doesn't scale with system size1
 Output that scales linearly with system size2
 (Debugging) output that scales quadratically with system size3
 (Debugging) output that scales cubically with system size
save_transition_density

Save the AO transition density matrix to file (in arma::arma_binary) format.
 The type is string
 There is no default value.
select_hole

Selectively converge the excited state with which the excitations are from the specified hole (i.e. occupied) orbitals.
 The type is [int]
 There is no default value.
spin

Specify spin of the excited states. If no input value is specified, the program will assign default value based on the spin of the reference calculation: for restricted closedshell reference state, the default spin for excited states will be
singlet
; otherwise, the default spin will bemixed
. The type is string
 There is no default value.
 The value must be one of:
singlet
 Solve for Singlet excited states only. Only effective for closedshell reference. This is the default for a closedshell reference state.triplet
 Solve for Triplet excited states only. Only effective for closedshell reference.mixed
 Solve for excited states of all POSSIBLE spin. This is the default for an unrestriced openshell reference state. For a closedshell reference, this will give both singlet and triplet excited states;