[SCF]: Self-Consistent Field (SCF) Options Controlling RHF, ROHF and UHF
[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.
**save_molden**
True
Option to save a Molden file.
**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**
1
Number of macro cycle attempts for SCF. If > 1, SCF restarts in a macro cycle until converged or maximum attempts.
**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).
[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_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.
forced_attempt: Control how many macro cycles the SCF attempts.
Default: 1 (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 converges or the maximum number of attempts is reached.
This is useful when dealing with tough convergence cases, such as low-temperature pFON runs.