Excited states, MRSF and properties¶

Source access and public downloads

Repository paths identify files in the licensed engine source; they are not public downloads. For freely downloadable .oqp inputs and results, see Worked Examples.

Source: gateway project 17, engine 1.3.1, commit 05361a3cc99fbad3da557084e41e21e690e5a27e. This parser reference is pinned to source version 1.3.1; it does not expand the capabilities of an installed 1.3.0 engine.

The response route owns nstate. Physical labels belong in grad(S1), opt(S0), nac(S0,S1) or another supported driver. Advanced solver controls use tdhf(...). MRSF reference multiplicity and target multiplicity have different meanings. Existing MRSF analytic NAC remains documented; no new NC/CV/NC-CV derivative support follows from this inventory.

Select response states explicitly¶

mrsf(nstate=3)/bhhlyp/6-31g* grad(S1)
geom="""
C      0.357265     0.223227    -0.756478
C      0.096381     0.077437     0.592011
H     -0.777577     0.294630    -0.911117
H      0.439342    -0.722961    -1.305394
H      0.454605     0.792671     1.330762
H     -0.570016    -0.665004     1.050215
"""

nstate is a positive integer response-root count. Omission permits inference from the requested states; an explicit count must contain every requested root. For MRSF, physical S0 is internal root 1 and S1 is root 2; the example lowers to properties.grad=[2]. For conventional TDDFT S0 instead denotes the SCF ground state. SF uses root=N, since spin character is diagnosed from the calculated states. Do not exchange these conventions.

Canonical request	Meaning and constraint
`tdhf(conv=1e-8,zvconv=1e-8)`	Response and Z-vector thresholds, independent of SCF convergence.
`nac(S0,S1,type=analytical)`	Existing MRSF analytic coupling; two distinct states are required. The parser requires suitably tight SCF/response/Z-vector thresholds.
`soc(ns=3,nt=5)`	Explicit separate singlet/triplet counts; do not also set route nstate.
`grad(S1)`	Selects a derivative, not an extra energy driver.

For a complete tight-threshold NAC example see migration. A parsed deck does not prove convergence, spin purity, NAC sign/gauge, or a model's derivative availability. Check the installed engine version and method support.

Exact-source keyword appendix¶

Scientific references¶

TDDFT; Spin-flip theory; MRSF-TDDFT; Spin-orbit coupling.

Source chain: canonical lowering (pyoqp/oqp/utils/oqp_input.py) → schema conversion (pyoqp/oqp/utils/input_parser.py) → calculation validation (pyoqp/oqp/utils/input_checker.py) → consumer entry point (pyoqp/oqp/library/single_point.py). Consumer source paths locate the relevant subsystem; they do not prove every listed key is read or executed.

tdhf¶

Detailed meaning, units and restrictions. These pages retain stable URLs and explain canonical controls; raw names identify schema storage, not sectioned input.

Raw section.key	Canonical spelling / ownership	Converter	Raw schema default
`tdhf.type`	`route / global / primary driver; see concepts`	`string`	`rpa`
`tdhf.maxit`	`tdhf(maxit=VALUE)`	`int`	`50`
`tdhf.maxit_zv`	`tdhf(maxit_zv=VALUE)`	`int`	`50`
`tdhf.multiplicity`	`route / global / primary driver; see concepts`	`int`	`1`
`tdhf.conv`	`tdhf(conv=VALUE)`	`float`	`1.0e-6`
`tdhf.nstate`	`route / global / primary driver; see concepts`	`int`	`1`
`tdhf.nstate_s`	`tdhf(nstate_s=VALUE)`	`int`	`0`
`tdhf.nstate_t`	`tdhf(nstate_t=VALUE)`	`int`	`0`
`tdhf.target`	`route / global / primary driver; see concepts`	`int`	`1`
`tdhf.zvconv`	`tdhf(zvconv=VALUE)`	`float`	`1.0e-6`
`tdhf.nvdav`	`tdhf(nvdav=VALUE)`	`int`	`50`
`tdhf.tlf`	`tdhf(tlf=VALUE)`	`tlf_order`	`0`
`tdhf.hfscale`	`tdhf(hfscale=VALUE)`	`float`	`-1.0`
`tdhf.cam_alpha`	`tdhf(cam_alpha=VALUE)`	`float`	`-1.0`
`tdhf.cam_beta`	`tdhf(cam_beta=VALUE)`	`float`	`-1.0`
`tdhf.cam_mu`	`tdhf(cam_mu=VALUE)`	`float`	`-1.0`
`tdhf.spc_coco`	`tdhf(spc_coco=VALUE)`	`float`	`-1.0`
`tdhf.spc_ovov`	`tdhf(spc_ovov=VALUE)`	`float`	`-1.0`
`tdhf.spc_coov`	`tdhf(spc_coov=VALUE)`	`float`	`-1.0`
`tdhf.conf_threshold`	`tdhf(conf_threshold=VALUE)`	`float`	`5.0e-2`
`tdhf.ixcore`	`tdhf(ixcore=VALUE)`	`string`	`-1`
`tdhf.z_solver`	`tdhf(z_solver=VALUE)`	`int`	`0`
`tdhf.gmres_dim`	`tdhf(gmres_dim=VALUE)`	`int`	`50`
`tdhf.resp_cutoff`	`tdhf(resp_cutoff=VALUE)`	`string`	`auto`
`tdhf.fp32`	`tdhf(fp32=VALUE)`	`string`	`auto`
`tdhf.zv_warmstart`	`tdhf(zv_warmstart=VALUE)`	`string`	`auto`
`tdhf.pair_cache`	`tdhf(pair_cache=VALUE)`	`bool`	`False`
## properties

Detailed meaning, units and restrictions. These pages retain stable URLs and explain canonical controls; raw names identify schema storage, not sectioned input.

Raw section.key	Canonical spelling / ownership	Converter	Raw schema default
`properties.scf_prop`	`properties(scf_prop=VALUE)`	`sarray`	empty
`properties.nmr_gauge`	`properties(nmr_gauge=VALUE)`	`string`	`cgo`
`properties.acid_spacing`	`properties(acid_spacing=VALUE)`	`float`	`0.2`
`properties.acid_padding`	`properties(acid_padding=VALUE)`	`float`	`5.0`
`properties.td_prop`	`properties(td_prop=VALUE)`	`bool`	`False`
`properties.grad`	`route / global / primary driver; see concepts`	`iarray`	`0`
`properties.grad_s`	`properties(grad_s=VALUE)`	`iarray`	empty
`properties.grad_t`	`properties(grad_t=VALUE)`	`iarray`	empty
`properties.nac`	`properties(nac=VALUE)`	`str`	empty
`properties.soc`	`properties(soc=VALUE)`	`bool`	`False`
`properties.export`	`properties(export=VALUE)`	`bool`	`False`
`properties.title`	`properties(title=VALUE)`	`str`	empty
`properties.back_door`	`properties(back_door=VALUE)`	`bool`	`False`
## nac

Detailed meaning, units and restrictions. These pages retain stable URLs and explain canonical controls; raw names identify schema storage, not sectioned input.

Raw section.key	Canonical spelling / ownership	Converter	Raw schema default
`nac.type`	`route / global / primary driver; see concepts`	`string`	`numerical`
`nac.dt`	`route / global / primary driver; see concepts`	`float`	`1`
`nac.dx`	`route / global / primary driver; see concepts`	`float`	`0.0001`
`nac.bp`	`route / global / primary driver; see concepts`	`bool`	`False`
`nac.nproc`	`route / global / primary driver; see concepts`	`int`	`1`
`nac.restart`	`route / global / primary driver; see concepts`	`bool`	`False`
`nac.clean`	`route / global / primary driver; see concepts`	`bool`	`False`
`nac.states`	`route / global / primary driver; see concepts`	`parray`	`1 2`
`nac.align`	`route / global / primary driver; see concepts`	`str`	`reorder`
## ekt

Detailed meaning, units and restrictions. These pages retain stable URLs and explain canonical controls; raw names identify schema storage, not sectioned input.

Raw section.key	Canonical spelling / ownership	Converter	Raw schema default
`ekt.ip`	`route / global / primary driver; see concepts`	`bool`	`True`
`ekt.ea`	`route / global / primary driver; see concepts`	`bool`	`False`