SCF, initial orbitals and quadrature¶

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.

Use scf(conv=1e-8), guess(type=huckel) and dftgrid(pruned=none) as exact calls. The route owns scf.type and scf.multiplicity; they cannot override its reference. Performance presets and recovery algorithms may change effective settings. The detailed pages explain units, finite option sets, convergence and fallback.

Converge the reference¶

hf/sto-3g scf(conv=1e-8,maxit=100) guess(type=huckel)
geom="H 0 0 0\nH 0 0 0.74"

Canonical control	Interpretation / constraint
`scf(conv=1e-8)`	Floating convergence threshold; tighter than raw default 1e-6. Numerical convergence must be checked for the intended observable.
`scf(maxit=100)`	Integer iteration limit; raw default 30. Raising it does not establish convergence.
`scf(maxdiis=7)`	DIIS history. Active EDIIS/ADIIS/VDIIS or nonzero-shift simplex stages require history <=13.
`scf(diis_type=cdiis)`	DIIS variant: none, cdiis, ediis, adiis or vdiis; raw default cdiis.
`guess(type=huckel)`	Initial orbital guess; restart/file guesses require their associated files.
`dftgrid(pruned=none)`	Quadrature control for DFT; not a model selector.

Select RHF/ROHF/UHF in the route and its reference options, not with scf(type=...) or scf(multiplicity=...). Those reserved calls fail rather than override the physical route. Effective recovery and performance presets can modify controls; consult the detailed convergence reference below.

Exact-source keyword appendix¶

Scientific references¶

SCF and response solvers; Functionals.

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.

guess¶

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
`guess.type`	`guess(type=VALUE)`	`string`	`huckel`
`guess.file`	`guess(file=VALUE)`	`str`	empty
`guess.file2`	`guess(file2=VALUE)`	`str`	empty
`guess.save_mol`	`guess(save_mol=VALUE)`	`bool`	`False`
`guess.continue_geom`	`guess(continue_geom=VALUE)`	`bool`	`False`
`guess.swapmo`	`guess(swapmo=VALUE)`	`string`	empty
## scf

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
`scf.type`	`route / global / primary driver; see concepts`	`string`	`rhf`
`scf.maxit`	`scf(maxit=VALUE)`	`int`	`30`
`scf.forced_attempt`	`scf(forced_attempt=VALUE)`	`int`	`2`
`scf.maxdiis`	`scf(maxdiis=VALUE)`	`int`	`7`
`scf.diis_reset_mod`	`scf(diis_reset_mod=VALUE)`	`int`	`10`
`scf.diis_reset_conv`	`scf(diis_reset_conv=VALUE)`	`float`	`0.005`
`scf.diis_type`	`scf(diis_type=VALUE)`	`string`	`cdiis`
`scf.cdiis_switch`	`scf(cdiis_switch=VALUE)`	`float`	`0.3`
`scf.vdiis_vshift_switch`	`scf(vdiis_vshift_switch=VALUE)`	`float`	`0.003`
`scf.vshift`	`scf(vshift=VALUE)`	`float`	`0.0`
`scf.mom`	`scf(mom=VALUE)`	`bool`	`False`
`scf.mom_switch`	`scf(mom_switch=VALUE)`	`float`	`0.003`
`scf.pfon`	`scf(pfon=VALUE)`	`bool`	`False`
`scf.pfon_start_temp`	`scf(pfon_start_temp=VALUE)`	`float`	`2000.0`
`scf.pfon_cooling_rate`	`scf(pfon_cooling_rate=VALUE)`	`float`	`50.0`
`scf.pfon_nsmear`	`scf(pfon_nsmear=VALUE)`	`float`	`5.0`
`scf.multiplicity`	`route / global / primary driver; see concepts`	`int`	`1`
`scf.conv`	`scf(conv=VALUE)`	`float`	`1.0e-6`
`scf.incremental`	`scf(incremental=VALUE)`	`bool`	`True`
`scf.pscreen`	`scf(pscreen=VALUE)`	`bool`	`False`
`scf.pscreen_k`	`scf(pscreen_k=VALUE)`	`float`	`1.0e-2`
`scf.pscreen_cap`	`scf(pscreen_cap=VALUE)`	`float`	`1.0e-8`
`scf.pscreen_tight`	`scf(pscreen_tight=VALUE)`	`float`	`1.0e-4`
`scf.pscreen_xc_dcut`	`scf(pscreen_xc_dcut=VALUE)`	`float`	`0.0`
`scf.pscreen_xc_aocut`	`scf(pscreen_xc_aocut=VALUE)`	`float`	`0.0`
`scf.pscreen_grid_rad`	`scf(pscreen_grid_rad=VALUE)`	`int`	`0`
`scf.pscreen_grid_ang`	`scf(pscreen_grid_ang=VALUE)`	`int`	`0`
`scf.xc_c2f`	`scf(xc_c2f=VALUE)`	`string`	`auto`
`scf.xc_phi_cache`	`scf(xc_phi_cache=VALUE)`	`string`	`auto`
`scf.xc_incdft`	`scf(xc_incdft=VALUE)`	`string`	`auto`
`scf.grad_cutoff`	`scf(grad_cutoff=VALUE)`	`string`	`auto`
`scf.init_scf`	`scf(init_scf=VALUE)`	`string`	`no`
`scf.init_basis`	`scf(init_basis=VALUE)`	`string`	`none`
`scf.init_library`	`scf(init_library=VALUE)`	`string`	empty
`scf.init_it`	`scf(init_it=VALUE)`	`int`	`15`
`scf.init_conv`	`scf(init_conv=VALUE)`	`float`	`0.001`
`scf.init_converger`	`scf(init_converger=VALUE)`	`string`	`None`
`scf.save_molden`	`scf(save_molden=VALUE)`	`bool`	`True`
`scf.rstctmo`	`scf(rstctmo=VALUE)`	`bool`	`False`
`scf.converger_type`	`scf(converger_type=VALUE)`	`string`	`diis`
`scf.scal_rel`	`scf(scal_rel=VALUE)`	`int`	`0`
`scf.scal_rel_decontract`	`scf(scal_rel_decontract=VALUE)`	`int`	`1`
`scf.stability`	`scf(stability=VALUE)`	`bool`	`False`
`scf.soscf_lvl_shift`	`scf(soscf_lvl_shift=VALUE)`	`float`	`0`
`scf.alternative_scf`	`scf(alternative_scf=VALUE)`	`string`	`trah`
`scf.escalation`	`scf(escalation=VALUE)`	`string`	empty
`scf.verbose`	`scf(verbose=VALUE)`	`int`	`1`
`scf.trh_stab`	`scf(trh_stab=VALUE)`	`bool`	`False`
`scf.trh_ls`	`scf(trh_ls=VALUE)`	`bool`	`False`
`scf.trh_sub_solver`	`scf(trh_sub_solver=VALUE)`	`string`	`davidson`
`scf.trh_nrtv`	`scf(trh_nrtv=VALUE)`	`int`	`1`
`scf.trh_r0`	`scf(trh_r0=VALUE)`	`float`	`0.4`
`scf.trh_jd_start`	`scf(trh_jd_start=VALUE)`	`int`	`30`
`scf.trh_nmic`	`scf(trh_nmic=VALUE)`	`int`	`50`
`scf.trh_gred`	`scf(trh_gred=VALUE)`	`float`	`0.001`
`scf.trh_lred`	`scf(trh_lred=VALUE)`	`float`	`0.0001`
`scf.trh_impl`	`scf(trh_impl=VALUE)`	`string`	`auto`
## dftgrid

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
`dftgrid.hfscale`	`dftgrid(hfscale=VALUE)`	`float`	`-1.0`
`dftgrid.cam_flag`	`dftgrid(cam_flag=VALUE)`	`bool`	`False`
`dftgrid.cam_alpha`	`dftgrid(cam_alpha=VALUE)`	`float`	`-1.0`
`dftgrid.cam_beta`	`dftgrid(cam_beta=VALUE)`	`float`	`-1.0`
`dftgrid.cam_mu`	`dftgrid(cam_mu=VALUE)`	`float`	`-1.0`
`dftgrid.rad_type`	`dftgrid(rad_type=VALUE)`	`string`	`ta`
`dftgrid.rad_npts`	`dftgrid(rad_npts=VALUE)`	`int`	`96`
`dftgrid.ang_npts`	`dftgrid(ang_npts=VALUE)`	`int`	`302`
`dftgrid.partfun`	`dftgrid(partfun=VALUE)`	`string`	`ssf`
`dftgrid.pruned`	`dftgrid(pruned=VALUE)`	`string`	`auto`
`dftgrid.grid_ao_pruned`	`dftgrid(grid_ao_pruned=VALUE)`	`bool`	`True`
`dftgrid.grid_ao_threshold`	`dftgrid(grid_ao_threshold=VALUE)`	`float`	`1.0e-15`
`dftgrid.grid_ao_sparsity_ratio`	`dftgrid(grid_ao_sparsity_ratio=VALUE)`	`float`	`0.9`