SCF - Open-Quantum-Platform/openqp GitHub Wiki

[SCF] Defaults

**Keyword**	**Default**	**Description**
**type**	rhf	Type of SCF calculation.
**maxit**	30	Maximum number of SCF iterations.
**maxdiis**	7	Maximum size of the DIIS matrix.
**diis_reset_mod**	10	Number of iterations before DIIS reset.
**diis_reset_conv**	0.005	DIIS reset criteria based on error threshold.
**diis_method_threshold**	2.0	Threshold for switching between DIIS methods.
**diis_type**	cdiis	Default DIIS method.
**vdiis_cdiis_switch**	0.3	Threshold for selecting cDIIS.
**vdiis_vshift_switch**	0.003	Threshold for applying vshift.
**vshift_cdiis_switch**	0.3	Threshold for cDIIS with vshift.
**vshift**	0.0	VSHIFT value.
**mom**	False	Enables the Maximum Overlap Method (MOM).
**mom_switch**	0.003	MOM activation threshold based on DIIS error.
**multiplicity**	1	Specifies the multiplicity for SCF.
**conv**	1.0e-6	Convergence criteria for DIIS.
**incremental**	True	Enables incremental Fock build.
**init_scf**	no	Initial SCF setting.
**init_it**	0	Initial iteration count.
**init_converger**	None	Initial scf converger.
**save_molden**	True	Option to save a Molden file.
**scal_rel**	0	Controls scalar relativistic correction for SOC-related calculations.
**pfon**	True	Enables Pseudo-Fractional Occupation Number (pFON) Method
**pfon_start_temp**	2000	specifies the initial temperature(K).
**pfon_cooling_rate**	50	sets the temperature reduction per iteration(K).
**pfon_nsmear**	5	controls the number of orbitals above and below the HOMO and LUMO for smearing.
**forced_attempt**	2	Number of macro cycle attempts for SCF. If > 1, SCF restarts in a macro cycle until converged or maximum attempts.
**alternative_scf**	"trah"	If forced_attempt > 1, the SCF restarts in a macro cycle using the converger specified by alternative_scf until convergence or the maximum number of attempts is reached.
**rstctmo**	False	Restrict MO ordering during SCF cycles. It is very similar to MOM method, but it restrict MO from the beginning. It is useful when you want to compute XAS (X-ray absorption spectroscopy).
**converger_type**	diis	Specifies the SCF converger.
**soscf_lvl_shift**	0	Level shifting parameter for SOSCF.
**soscf_reset_mod**	0	Reset mode for SOSCF orbital Hessian. 0 = no reset (default), n > 0 = reset every n iterations if the gradient norm ratio exceeds 95%.
** trh_stab **	False	stability.
** trh_ls **	False	line_search.
** trh_dav **	True	davidson.
** trh_jd **	False	jacobi_davidson.
** trh_pjd **	False	prefer_jacobi_davidson.
** trh_nrtv **	1	n_random_trial_vectors.
** trh_r0 **	0.4	start_trust_radius.
** trh_nmic **	50	n_micro.
** trh_gred **	0.001	global_red_factor.
** trh_lred **	0.0001	local_red_factor.

[SCF] Details

The **scf** section handles time-independent calculations.

• type: Choose the type of wavefunction.
  • Options:
    • rhf: Restricted Hartree-Fock/Kohn-Sham. (Default)
    • uhf: Unrestricted Hartree-Fock/Kohn-Sham.
    • rohf: Restricted Open Hartree-Fock/Kohn-Sham.
• maxit: Set the maximum number of SCF iterations.
  • Default: 30
• maxdiis: Set the maximum number of dimensions for the DIIS converger.
  • Default: 7
• diis_type: Specify the type of DIIS.
  • Default: cdiis: Commutator-based DIIS.
  • Options:
    • adiis: Augmented Direct Inversion in the Iterative Subspace.
    • ediis: Energy-based DIIS.
    • vdiis: Variable DIIS with dynamic switching.
• diis_reset_mod: Specify the number of iterations before checking for a DIIS reset.
  • Default: 10
• diis_reset_conv: Set the threshold for the DIIS reset.
  • Default: 0.005
• multiplicity: Set the multiplicity of the reference state.
  • Default: 1
• conv: Set the energy convergence criteria.
  • Default: 1.0e-6
• incremental: Use the incremental Fock method.
  • Options:
    • True: Use the incremental method. (Default)
    • False: Do not use the incremental method.
• init_scf: Perform an initial SCF iteration to aid convergence.
  • Options:
    • rhf: Perform an initial RHF-type HF calculation, regardless of the functional.
    • uhf: Perform an initial UHF-type HF calculation, regardless of the functional.
    • rohf: Perform an initial ROHF-type HF calculation, regardless of the functional.
    • rks: Perform an initial RKS-type DFT calculation according to the functional.
    • uks: Perform an initial UKS-type DFT calculation according to the functional.
    • roks: Perform an initial ROKS-type DFT calculation according to the functional.
    • no: Do not perform an initial SCF iteration. (Default)
• init_it: Set the maximum number of initial SCF iterations.
  • Default: 0
• save_molden: Save orbitals.
  • Options:
    • True: Save orbitals to a Molden file.
    • False: Do not save orbitals.
• scal_rel: Controls scalar relativistic correction support used by SOC-related workflows.
  • Default: 0
• forced_attempt: Control how many macro cycles the SCF attempts.
  • Default: 2 (Normal SCF with a single cycle).
  • If forced_attempt > 1, the code will perform multiple macro cycles of SCF. After each cycle, if the SCF has not converged, it restarts until it
• alternative_scf: Specifies the alternative SCF converger used when the normal SCF fails to converge.
  • Default: "trah"
  • If forced_attempt > 1, the SCF restarts in a macro cycle using the converger defined by alternative_scf (e.g., TRAH) after each failed attempt, continuing until convergence is achieved or the maximum number of attempts is reached.
    converges or the maximum number of attempts is reached.
  • This is useful when dealing with tough convergence cases, such as low-temperature pFON runs.
• converger_type: Specify the type of SCF converger.
  • Default: diss: This is default.
  • Options:
    • soscf : Second-order scf.
    • trah : Trust-region augmented hessian.
• init_converger: Specify the initial convergence method.
  • Default: 0: Use DIIS as the initial method.
  • Options:
    • 1: Use SOSCF as the initial convergence method.

Back to Input File System with PyOQP