Overlay 6

6/7   6/8   6/9   6/10   6/11   6/12   6/8-12   6/13   6/14   6/15   6/16   6/17   6/18   6/19   6/20   6/22   6/23   6/24   6/25   6/26   6/27   6/28   6/29   6/30   6/31   6/32   6/35   6/36   6/37   6/38   6/39   6/40   6/41   6/42   6/43   6/44   6/45   6/46   6/47   6/48   6/49   6/50   6/51   6/52   6/53   6/54   6/55   6/56   6/57   6/58   6/59   6/60-62   6/63   6/64   6/65   6/72   6/73   6/74   6/75   6/76   6/77   6/78   6/79   6/80   6/81   6/82   6/83   6/84   6/86   6/87   6/88   6/89   6/90   6/91   6/92   6/93   6/94   6/95   6/96   6/113   6/114   6/120   6/124   6/125   6/126   6/127   6/128   6/129

Overlay 6


Printing of MOs.

0 Default: 1 for molecules, 2 for PBC.
1 Print the occupied and first 5 virtual MOs.
2 Do not print any MOs.
3 Print all MOs.
10 Biorthogonalize unrestricted MOs.
100 Save biorthogonalized MOs over canonical ones.


Density matrix. Default: No-print. See below for values.


Full population analysis. Default: Print. See below for values.


Gross orbital charges. Default: Print. See below for values.


Gross orbital type charges. Default: No-print. See below for values.


Condensed to atoms. Default: Print. See below for values.


These options are print/no-print options. The possible values are:

0 Default.
1 Print the normal amount.
2 Do not print.
3 Print verbosely.


Whether to save computed electric field on disk for use in Tomasi RF calculations.

0 Default (No).
1 Yes.
2 No.


0 Default (1).
1 Evaluate the electric potential, the electric field, and the electric field gradient at each center.
2 Evaluate the potential and the electric field at each center.
3 Evaluate only the potential at each center.
4 Evaluate none.


Specification of additional centers. If more than one of these is requested, the lists are in separate input sections in the order listed below.

0 No additional centers. Evaluate the properties only at each atomic center.
1 Read additional centers. One card per center with the X, Y, and Z coordinates in Angstroms (free format).
2 Read in coordinates as for 1. Starting at each point, located the nearest stationary point in the electric potential.
4 Read in a set of cards specifying a grid of points at which the electric potential will be computed. Two forms of specifications are below.
8 Do potential-derived charges.
16 Constrain the dipole in fitting charges.
32 Read in centers at which to evaluate the potential from the RWF.
128 Read grid; do not default cube.

Grid specifications for option 4

A. Evenly spaced rectangular grid. Three cards are required:

KTape,XO,YO,ZO —output unit and coordinates of one corner of grid. If KTape is 0, it defaults to 51.
N1,X1,Y1,Z1 —number of increments and vector.
N2,X2,Y2,Z2 —number of increments and vector.

N1 records will be written to unit KTape, with N2 values in each record.

B. An arbitrary list of points. Only one card is needed: N,NEFG,LTape,KTape.

The coordinates of N points in Angstroms will be read unit LTape in format (3F20.12). The potential (NEFG=3), potential and field (NEFG=2), or potential, field, and field gradient (NEFG=1) will be computed and written along with the coordinates to unit KTape in format (4F20.12). Thus if NEFG=3 for each point there will be 4 cards written per point, containing:


Note that either form of grid should be specified with respect to the standard orientation of the molecule.


0 Use full accuracy in calculations at specific points, but use sleazy cutoffs in mapping a grid of points.
1 Do all points to full accuracy.


0 Compute all contributions to selected properties.
1 Compute only the nuclear contribution.
2 Compute only the electronic contribution.
-N Compute only the contribution of shell N.


Whether to update dipole RWF.

0 Yes.
1 No.


Whether to rotate exact polarizability before comparing with approximate (which will be calculated in the standard orientation). This is like IOp(6/9) in L9999.

0 Default, same as 1.
1 Exact is still in standard orientation; use as-is.
2 Exact is already in z-matrix orientation, so rotate.


How to do electrostatic-potential derived charges.

0 Default (1).
-1 Read a list of points at which to fit, one per line.
1 Merz-Kollman point selection.
2 CHELP point selection.
3 CHELPG point selection.
4 MK but with 2xUFF radii.
5 Hu, Lu, and Yang point selection/weighting. By default, HLY’s atomic densities are used. These are available only up to Ar.
00 Default radii are those defined with the selected method.
10 Force Merz-Kollman radii.
15 Use Gaussian’s atomic density expansions instead of HLY’s. Gaussian’s are defined for all elements up to 112.
20 Force CHELP (Francl) recommended radii.
30 Force CHELPG (Breneman) recommended radii.
40 Force 2xUFF Radii.
100 Read in replacement radii for selected atom types as pairs (IAn,Rad) or (Symbol,Rad), terminated by a blank line.
200 Read in replacement radii for selected atoms as pairs (I,Rad), terminated by a blank line.
1000 Fit united atoms (heavy atoms only) rather than all atoms.
00000 Default (10000).
10000 Use only active atoms in the fit.
20000 Use all atoms in the fit.
30000 Fix the charges of all atoms with a non-zero MM charge.


-1x Read density matrices from .checkpoint file.
+1x Read density matrices from .checkpoint file.
-5 All available transition densities.
-4 Transition density between the states given by IOp(6/29) and IOp(6/30).
-3 Density for the excited state given by IOp(6/29).
-2 Use all available density matrices.
-1 Use the density matrix for the current method, or the HF density if the one for the current method is not available.
N≥0 Use the density matrix for method N (see Link 1 for the numbering scheme).


0 Default (same as 3).
1 Density values.
2 Density values and gradients.
3 Density values, gradients and divergence.


Frozen core.

-N Freeze N orbitals.
0 Default (Yes).
1 Yes.
2 No.


0 No.
1 Yes, classically (including self terms — requires 2e integrals, O(N4)).
2 Yes, quantum mechanically (no self terms — requires 2e integrals, and only available for HF. O(N5)).


0 Default (same as 1).
1 Total.
2 Alpha.
3 Beta.
4 Spin.


Choice of population analysis.

0 Default (12).
1 Don’t do Mulliken populations.
2 Do Mulliken populations.
10 Don’t do bonding Mulliken populations.
20 Do bonding Mulliken populations.
100 Do minimal population analysis.
1000 Read in weightings for atoms pairs for unequally split Mulliken.


Mark SCF density as current density.

0 No: save SCF density, but do not mark.
1 Yes: mark as well.


Excited state to use if requested by IOp(6/22).


2nd excited state for transition density.

0 Transition density between state IOp(6/29) and g.s.
N Transition density between state IOp(6/29) and state N.


Whether to determine natural orbitals from densities.

0 No.
1 Yes, using total density.
2 Yes, using alpha and beta separately for UHF.
3 Store only alpha NOs.
4 Store only beta NOs.
5 Use spin density.


100000*IPrSma+10000*MItLoc+1000*ITlLoc+100*IDcInt+IPrLoc, where:

IPrSma When printing MOs in terms of AOIMs, include only MOs with occupancies per spin greater than 10-IPrSma and AOIMs with squares of coefficients greater than 10-IPrSma (1…9, the default of 0 implies printing of all MOs and AOIMs).
MItLoc MItLoc*NOrb*(NOrb-1)/2 is the maximum number of iterations in localization of (spin) orbitals (1…9, default 6).
ITlLoc 10.-ITlLoc is the convergence criterion for (spin)orbital localization (1…9, default 9).
IDcInt Localized (spin)orbitals with atomic occupancies less than 0.01*IDcInt are interpreted as lone pair MOs rather than bond MOs (1…99, default 10).
IPrLoc 0: Print the atomic occupancies of localized (spin)orbitals (default).
1: Do not print the atomic occupancies.
0 Make this a scratch file.
1 Name this file ‘rpac.11’


0 Determine attractors, attractor interaction lines, ring points, and cage points.
1 Determine zero-flux surfaces (IDoZrF).
2 Compute charges of AIMs (IDoAtC).
4 Compute kinetic energies and multipole moments of AIMs (IDoPrp).
10 Compute energies of electrostatic interactions between AIMs (IDoPot). This precludes calculations of atomic property derivatives with respect to nuclear displacements.
100 Compute atomic overlap matrices (IDoAOM).
200 Compute other atomic matrix elements (IDoAMa).
400 Include zero-flux surface relaxation terms in all atomic matrix elements (IDoSRe).
1000 Compute derivatives of atomic properties with respect to electric field (IDoSeP). Note that IDoSRe should be set to 1 in order to obtain correct results! Also note that analytical polarizabilities have to be available but force constants have to be absent!
2000 Compute derivatives of atomic properties with respect to nuclear displacements as well (IDoNuD). Note that analytical force constants have to be available!
10000 Compute localized orbitals and bond orders (IDoLoc).
20000 Compute atomic orbitals in molecule (IDoAOs).
100000 If necessary, augment valence electron densities with relativistic core contributions, which is a default anyway (IHwAug = 0).
200000 If necessary, augment valence electron densities with non-relativistic core contributions (IHwAug = 1).
400000 Abort if pseudo-potentials have been used (IHwAug = 3).
1000000 Reduce accuracy so atomic charges can be computed more rapidly (IQuick). No other properties can be calculated. This option sets IPrNDe=5, IPrNA t= 5, and IEpsIn = 100.
2000000 Use numerical instead of analytic integration.
3000000 Use numerical instead of analytic integration and use reduced cutoffs.
4000000 Full accuracy and analytic integration.


10000*INoZer+100*IPrNDe+IPrNAt, where…

INoZer 0: Ignore (spin)orbitals with zero occupancies (default).
1: Do not ignore (spin)orbitals with zero occupancies.
IPrNDe Neglect primitive contributions below 10.-IPrNDe in evaluations of electron density and its derivatives (0…99, default 7).
IPrNAt Neglect primitive contributions below 10.-IPrNAt in integrations over atomic basins (0…99, default 7).


1000000*MxBpIt+100000*SBpMax+1000*NGrd+LookUp, where…

MxBpIt Maximum number of iterations in trial path determination (1…99, default 10).
SBpMax Maximum value of the control sum (1…9, default 2).
NGrd Length of Fourier expansion for the trial path (1…99, default 20).
LookUp Number of grid points in critical point search (1…999, default 100).



INStRK 10*INStRK is the number of steps in the Runge-Kutta integrations along gradient paths (1…9, default 2).
IHowFa IHowFa is the maximum distance in the Runge-Kutta integrations along gradient paths (1…9, default 5),
IGueDi 10.-IGueDi is the initial displacement from the critical point in the Runge-Kutta integrations (1v9, default 6).
IPraIn 10.*IPraIn is the cut-off for zero-flux surfaces (1…9, default 2).
IRScal IRScal is the scaling factor in the nonlinear transformation used in the intersection search (1…9, default 2).
IRtFSe 10.*IRtFSe is the safety factor used in the intersection search (1…9, default 2).



IToler 10.-5-IToler is the tolerance for the intersection search (1…9, default 5).
INInGr 10*INInGr is the initial number of grid points in theta and phi in the adaptive integration subroutine (1…9, default 2).
INInCh 5+INInCh is the initial number of sampling points in the intersection search (1…9, default 2).
IEpsSf IEpsSf is the safety factor used for patches with surface faults in the adaptive integration subroutine (1…9, default 6).
IEpsIn 0.0001*IEpsIn is the target for integration error (1…99, default 2).
INTrig 10*INTrig is the number of sine and cosine functions in the trial function for surface sheets (1…9, default 2).


-2 Skip NBO analysis.
-1 Do only NPA.
0 Default (-2).
1 Default NBO analysis — don’t read input.
2 Read input data to control NBO analysis.
3 Delete selected elements of NBO Fock matrix and form a new density, whose energy can then be computed by one of the SCF links. This link must have been invoked with IOp(40) = 0 or 1 prior to invoking it with IOp(40) = 2.
4 Read the deletion energy produced by a previous run with IOp(40) = 2 and print it.
10 NBO should not delete its internal data file.


Number of layers in esp charge fit.

0 Default (4).
N N layers, must be ≥ 4.


Density of points per unit area in esp fit.

0 Default (1).
N Points per unit area.


Increment between layers in MK charge fit.

0 Default (0.4/Sqrt(#layers)), where # layers = IOP (6/41)
N 0.01*N.


0 Default, same as 2.
1 Compute the molar volume.
2 Evaluate the density over a cube of points.
3 Evaluate MOs over a cube of points.
10 Skip header information in cube file.


Number of points per Bohr3 for Monte-Carlo calculation of molar volume.

-1 Read from input.
0 Default (20).
N N points — for tight accuracy, 50 is recommended.


Threshold for molecular volume integration.

0 Default — 10-3
-1 Read from input.
N N*10-4.


Scale factor to apply to van der Waals radii for the box size during volume integration.

0 Default.
N N*0.01 — for debugging.


Use of cutoffs.

0 Default (10-6 accuracy for cubes, 1 digit better than desired accuracy for volumes).
N 10-N.


0 Default (80).
N N points.
-1 Read from cards.
-2 Coarse grid, 3 points/Bohr.
-3 Medium grid, 6 points/Bohr.
-4 Fine grid, 12 points/Bohr.
-N>4 Grid using 1000 / N points/Bohr.


Whether to write Antechamber file during ESP charge fitting.

0 Default (No).
1 Yes.


Whether to apply Extended Koopman’s Theorem (EKT).

0 Default (No).
N Yes, on non-SCF densities, up to N IPs and EAs.
-1 Yes, on non-SCF densities, all possible IPs and EAs.
-2 No.


0 Default (100).
N N.


0 Default (cubic).
N Polynomial of order N.


Maximum number of domains.

0 Default (100000).
N N.


-1 0(no inner sphere).
0 302.
N N point Lebedev grid (see AngQad).


0 No.
1 Yes.


Whether to generate data over a grid using the total SCF density.

0 No.
1 Yes, read in name for output file.
2 Yes, also read in name for input file with a different grid and compare.
3 Output in the form of data statements.
4 Fit atomic density to Gaussians.
5 Fit atomic density to Gaussians, forcing positive definiteness.


Grid to use in generating tables of density and potential if IOp(57) = 1–3. Must be an unpruned grid.

0 Default (99001).

If IOp(57) = 4–5, whether to remove primitives which have all zero coefficients in the expansion:

0 Default (1).
1 Yes.
2 No.


Approximations to Exc

-1 Test superposition of atomic densities using L608:
0 Do correct energies.
1 Do correct energies and 0th order approximation.
2 Do correct energies and 0th-1st order approximations.
3 Do correct energies and 0th-2nd order approximations.


Over-ride standard values of IRadAn, IRanWt, and IRanGd. The default is 3 steps smaller grid for HLY charges in L602 and the global default otherwise.


0 Default (do test).
1 Suppress test.
2 Do test as usual.


Natural Chemical Shielding Analysis.

0 No.
1 Yes, of isotropic value.
2 Yes, of diagonal tensor elements and isotropic value.
3 Yes, of all tensor components.


Threshold for printing of NCS contributions.

-1 Zero.
0 Default (1 pmm).
N N/1000 ppm.


0 Default (1).
1 Yes, if open-shell, NMR data is available, and other terms are being computed.
2 No.
3 Yes, regardless of other terms.
4 Yes, reading isotopes.


Whether to save orbitals from NBO.

0 Default (No).
1 Save NBOs in place of regular MOs.
2 Save NLMOs in place of regular MOs.
3 Save NLMO occupieds and NBO virtuals.
10 Suppress re-orthogonalization.
110 Suppress sorting.


Whether to use Gaussian connectivity in choosing Lewis structure for NBO.

0 Default (use if present and choose is selected in NBO input).
1 Use.
2 Don’t use.



0 Default (1.D-6).
N 10-N.


0 None.
-1 2.d-4.
N N * 10-5.


Use MOs instead of density in AtmTab.

0 Default (2).
1 Use density.
2 Use MOs.


Whether to calculate Hirshfeld charges.

0 Default (No).
1 Yes.
2 No.
3 Yes, do atom-atom electrostatic interactions as well.
10 Do iterative charges.
20 Do iterative charges and read initial values.
100 Do partitioning of density by abelian irrep.
NNNxxx Maximum number of iterations. Default is 50.


Whether to calculate Lowdin charges and Mayer bond orders.

0 Default (No).
1 Yes.
2 No.


Print kinetic energy of orbitals?

0 Default (yes, if doing other orbital results).
1 Yes, for the top 5 occupieds and lowest 5 virtuals.
2 No.
3 Yes, for all orbitals.


Tensors for hyperfine spectra.

0 Default, compute if there are 100 or fewer atoms.
1 Compute QEq tensors and for open-shell systems compute isotropic and anisotropic splitting tensors.
2 Do not compute tensors.


Orbital angular momentum analysis.

0 Default (No).
1 Yes, do total angular momentum contribution to each MO.
10 Report the largest atomic d and f contributions to orbitals specified by IOp(6/84).
20 Report the largest transition metal atomic d and f contribs. to orbitals specified by IOp(6/84).
30 Read a list of atoms whose d and f contributions will be analyzed.
90 Do not do atomic d and f contributions.
100 Report the population of each angular momentum on each atom.


Orbitals to analyze for d and f contributions.

-1 All orbitals.
0 Just occupied orbitals.
N Occupieds plus lowest N virtuals.


Computation of multipole moments.

0 Default (1, except for PBC and old semi-empirical).
1 Calculate with DipInt.
2 Use stored moment operators.


0 Default.
N 10-N


Thresholds for orbital atomic angular momentum printing.

0 Default (10%).
NN At least NN % to print contribution from L on a particular atom.


Do Natural Transition Orbital Analysis.

0 No.
1 Yes, if ground to excited transition density requested.
10 Save over canonical MOs.


Whether to include p’s as valence for transition metals and actinides during NBO analysis.

0 Default (Yes).
1 Yes.
2 No.


Whether to compute electron-electron spin-spin coupling.

0 No.
1 Yes, if multiplicity >2.


Thresholds for HLY charge fitting.

0 Default (Tiny=1.d-8, ThrGrd=1.D-8)
MMNN Tiny=10-MM, ThrGrd=10-NN.


Reference density for HLY charge fitting.

-1 Zero.
0 Exp(-9)
N N/100.


Sigma parameter for HLY charge fitting.

0 0.8.
N N/1000.


0 Default (No).
1 Yes, with Davidson.
2 Yes, with DiagDN.


Analyze all orbitals by atom and angular momentum contribution.

0 Default (No).
-2 Highest 10 occupieds and lowest 10 virtuals.
-1 Yes, for all orbitals.
N For highest N occupieds and lowest N virtuals.


0 Default (1).
N Command N in file 747.


Which ONIOM system is being done, which is sometimes needed by external procedures.

0 Default (1)
1 Real system.
2 Model system for 2-layer, middle for 3-layer.
3 Small model system for 3-layer.


Store nuclear repulsion energy as total energy? (Here, store only the nuclear contribution to the dipole moment).

0 Default (no).
1 Yes.




-1 Same as 0.
0 Default to Gau_External.
1 Default to runnbo6.


Whether to compute BEBO energy corrections.

0 Default (1 if parameters available).
1 Yes.
2 No.
00 Default (10).
10 Use number of pairs (including core) rather than number of lone pairs.
20 Use number of lone pairs.


0 Default (01).
1 Do regular calculations.
10 Do core-valence.
11 Do both.


Whether to do DCT charge transfer analysis on the selected excited state densities:

1 Do the analysis if excited state densities are available, and for the relaxed excited state density if this was selected.
NNNx Do a maximum of NNN matrices at a time.

Last updated on: 30 August 2022. [G16 Rev. C.01]