Overlay 8

IOp(8/5)

Whether to pseudo-canonicalize ROHF orbitals.

-2	Yes, and save over canonical MOs setting ILSW for UHF.
-1	Yes.
0	Default (Yes if ROHF).
1	No.

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IOp(8/6)

Bucket selection.

0	Buckets for MP2: (IA/JB).
1	Buckets for stability: (IA/JB), (IJ/AB).
2	Buckets for CID or MP3: (IJ/AB), (IA/JB), (IJ/KL).
3	Buckets for semi-direct MP4DQ, CISD, QCISD, BD: (IJ/AB), (IA/JB), (IK/KL), (IJ/KA).
4	CISD or MP4SDQ or MP4SDTQ, but includes (IA/BC).
5	The complete set of transformed integrals.
6	Full transformation if this is consistent with MaxDisk, otherwise same as 3.
7	Full transformation if this is consistent with MaxDisk, otherwise same as 4.

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IOp(8/7)

SCF convergence test.

0	Test that SCF has converged.
1	Do not test SCF convergence (mainly used for testing).

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IOp(8/8)

L811: Whether to delete MO integrals.

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

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IOp(8/9)

L804: Direct Transformation Control.

0	Operate normally.
1	Generate and test RInt3 array (L804).
2	Accumulate MP2 force constant terms in direct fashion.
3	Write the MO basis first derivative ERI’s to disk.
10	Force fully in-Core algorithm (L804 only).
20	Force transformed integrals in Core algorithm.
30	Force semi-direct transformation.
100	Force output bucket in Core anti-symmetrization.
200	Force sorting for output bucks.
1000	Force semi-direct mode 1.
2000	Force semi-direct mode 2.
3000	Force semi-direct mode 3 if IOp(8/6)=3.
4000	Force semi-direct mode 4 if IOp(8/6)=3.
00000	Default (10000).
10000	Do not symmetry compress transformed integrals.
20000	Do symmetry compress transformed integrals (buckets) (This will cause windowed MOs, reordered in the order of representations like occ-rep1,occ-rep2,… virt-rep1,virt-rep2,… eigenvalues and symm. assignment vectors will be put in correspondence with vectors. VGZ).
30000	Symmetry compress transformed integrals only if RHF. (Upper triangle of symmetry compressed integrals for IOp(8/6)=5 or 4 only! (VGZ)).
40000	Store buckets of single-bar integrals, not symmetry compressed.
100000	Reorder MOs, eigenvalues and symmetry assignment vectors according to the representations.

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IOp(8/10)

Window is selected as follows:

-N	Use the top N occupieds and lowest N virtuals.
0	Default, same as 4.
N	1 ≤ N ≤ 89 selects frozen-core type N.
1	The largest noble gas core is frozen.
2	G2 frozen-core: the largest noble gas core and main group d orbitals are frozen, except that the outer sp electrons of 3rd row and later alkali and alkali earth elements are retained.
3	The next to the largest noble gas core is frozen.
4	The largest noble gas core and main group d’s are frozen.
5	G3 frozen-core: the largest noble gas core is frozen, except that the outer sp electrons of 3rd row and later alkali and alkali earth elements are retained.
6	G4 frozen-core: the largest noble gas core is frozen, except that the outer sp electrons of 2nd row and later alkali and alkali earth elements are retained. For basis sets with double-zeta cores, core virtuals are also frozen.
7	CBS-Wes core: noble gas except 3sp valence K-Zn, 3d valence Ga-As.
90	Use all MOs.
91	The window is specified by IOp(8/37-38). If IOp(8/37) is 0, a card is read in indicating the start and the end. A negative value for the end deletes the top virtuals.
92	The window is recovered from RWF 569.
93	The window is recovered from file 569 on the checkpoint file.
94	Read a list of orbitals to freeze.
000	Default (200).
10x	Use orbital energies to choose core orbitals.
20x	Use overlap with atomic core orbitals from Harris to choose core orbitals.
30x	Use overlap with atomic core orbitals from Core Ham to choose core orbitals.

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IOp(8/11)

MO coefficient, orbital energy, and number of electrons test.

0	Default, same as 2 except for during BD iterations or BD=Read.
1	Just print a warning message.
2	Kill the job if any MO coefficients are greater than 1000.0 or the smallest difference between occupied and virtual orbital energies is less than 0.001. Also, kill a frozen-core job if there is significant core-valence mixing in the canonical orbitals.
00	Default, same as 10.
10	Suppress such a test (CPHF may still be done for such a case).
20	Kill the job if there is no corr. energy; e.g., if there is only 1 electron or 1 virtual spin-orbital.

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IOp(8/16)

L811: Maximum number of orbitals per pass (only if integral derivative file is being written). Default is as many as fit with Max Disk.

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IOp(8/18)

L811: Which type of derivative transformation to do.

0	Default, same as 3.
1	Non-canonical, Uij,x = -1/2 Sij,x.
2	Canonical, Uij,x = (Fij,x – EjSij,x) / (Ei-Ej) Note that this blows up for degenerate orbitals and is intended primarily for debugging.
3	Non-canonical, Uij,x = -1/2 Sij,x, except canonical in frozen-active blocks.
4	Non-canonical, Uij,x = -Sij,x Uji,x = 0.
5	Canonical occupieds, Uab,x = -Sab,x/2.
6	Canonical virtuals, Uij,x = -Sij,x/2.

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IOp(8/19)

L811: The nature of the perturbation(s).

0	Default (1st order nuclear and electric field).
IJK	Nuclear Kth order. Electric field Jth order. Magnetic field Ith order.

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IOp(8/20)

L811: Which terms to include.

0	Default (same as 11).
1	MO derivative times integral term.
10	MO times integral derivative term.

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IOp(8/23)

L811: Algorithm control.

0	Default (32).
1	Unused.
2	Accumulate MP2 force constant terms in direct fashion.
3	Write the MO basis first derivative ERI’s to disk.
20	Force fully direct.
30	Force semi-direct.

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IOp(8/24)

Whether to try to transform old amplitudes on the checkpoint file.

0	Default: 1 if doing BD=Read and amplitudes are present; 2 otherwise.
1	Yes.
2	No.
10	Transform Z-amplitudes as well.
20	Do not transform Z-amplitudes as well.
000	Default, transform EOM amplitudes if transforming ground-state ones.
100	Transform EOM amplitudes.
200	Do not transform EOM amplitudes.

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IOp(8/28)

L921, L922: Hack number of occupieds for full CI.

-1	Transform all orbitals (after freezing core) as occupieds (i.e., set NOA=NOB=NROrb in transformation).
0	No.
N	Transform N orbitals (after frozen core) as occupieds (i.e., set NOA=NOB=N for purposes of transformation).

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IOp(8/29)

L811: Requested diskusage. This will determine the number of times AO integrals and derivatives are evaluated unless overridden by IOp(8/31). This only applies if the integral derivatives are not stored.

-3	Use as much as desired, independent of MAXDISK.
-2	Use an amount which is similar to the maximum disk usage in other parts of the MP2 freq. code.
-1	Use as much as needed for maximum efficiency, subject to the limit imposed by MAXDISK.
0	Default (-1).
N	N evaluations and hence N coarse tiled batches (1…6 are the currently implemented options).

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IOp(8/30)

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IOp(8/36)

Whether to update force constants with the MP2 product of MP2 integral derivatives term (only applies if integral derivative file is not written).

0	Default (Yes).
1	Yes.
2	No.
00	Default on whether to make Poo and Pvv for MP2. (Yes if Ix is not stored, no otherwise).
10	Yes.
20	No.

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IOp(8/37)

Integer specifying first window parameter (n).

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IOp(8/38)

Integer specifying second window parameter (m).

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IOp(8/39)

Localized orbital method adopted in SAC/SAC-CI.

0	Default. No localization.
1	Boys method.
2	Population method.
3	Boys + population method.

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IOp(8/40)

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IOp(8/41)

Transformation of spin-orbitals (alpha only) within occupied and unoccupied orbital subspaces by minimum orbital-deformation (MOD) method.

0	Default. No.
1	No, but save MOs.
2	Yes. Take reference MOs from disk if available.
3	No for the 1st geometry of opt, yes otherwise.

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IOp(8/42)

Whether to reorder MOs during potential surface exploration.

0	No.
1	Yes.
2	Yes (for SAC-CI single point calculation).
00	Use orbital energies in ordering.
10	Don’t use orbital energies in ordering.
000	Use second moments in ordering.
100	Don’t use second moments in ordering.
0000	Use dipole moments in ordering.
1000	Don’t use dipole moments in ordering.

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IOp(8/46)

Indicates special case of non-HF calculation.

0	Default – MOs are canonical HF orbitals.
1	Input orbitals are not canonical HF and pseudo-canonical orbitals must be generated here for the post-SCF.
10	Generate HF pseudo-canonical even if the original SCF method was not (i.e., Kohn-Sham).

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IOp(8/47)

Whether L804/L811 should generate results compressed over active atoms.

0	Default (2).
1	Active atoms.
2	Full list.
3	Full list, but blank contributions from inactive atoms (no difference from 2 for overlay 8).
4	Active atoms, and store Hessian contributions over active atoms only.

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IOp(8/60-62)

Over-ride standard values of IRadAn, IRanWt, and IRanGd. For DFTCV, IRadAn defaults to 299974 rather than the global default.

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IOp(8/68)

EOM-CCSD

0	No EOM.
1	Do EOM with the default algorithm (right and left spaces separately).
11	Do EOM doing only the transition energy (right space).
21	Do EOM doing right and left eigenvectors using the same expansion space for both.
31	Do EOM doing right and left eigenvectors using biorthogonal expansion spaces.

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IOp(8/69)

EOM: Number of states per irreducible representation (largest Abelian subgroup) to do.

0	Default (2).
N	N per irreducible representation.
-1	Read the number for each irreducible representation, all from one line.

The order of irreducible representations is the same as printed for symmetry-adapted basis functions by L301.

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IOp(8/87)

Accuracy of integrals.

0	Default (12).
N	10-N.

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IOp(8/105)

Convergence of amplitudes for EOM iterations.

0	Default (1.d-5).
N	10-N.

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IOp(8/106)

Number of EOM states for LR transition densities.

0	Default (None).
-1	All.
N	First N of each symmetry.

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IOp(8/107)

EOM state of most interest.

0	Default (1st excited state).
N	Nthexcited state.

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IOp(8/108)

EOM-CCSD: Total number of states to do. Guesses are taken from the checkpoint file if RdAmp was specified, with remaining states taken from the CIS guess in CIS energy order.

0	Default (2*NIrrep)

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IOp(8/109)

IFact for Davidson in EOM-CC.

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IOp(8/110)

State-to-State transition dipoles in EOM-CC:

0	None.
1	From state NRoot to higher states.
2	From state NRoot to higher and lower states.

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IOp(8/111)

MaxIt for EOM.

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IOp(8/112)

MaxMin for EOM.

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IOp(8/113)

WhenSc for EOM.

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IOp(8/114)

IRdLft for EOM.

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IOp(8/115)

IFirst for EOM.

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IOp(8/116)

Compute DFT estimate of core-core and core-valence correlation?

0	Default.
1	Yes.
2	No.
10	Include empirical corrections for total energies.
20	Do not include empirical corrections.

The default is not to compute the correction, and if the correction is requested, to include the total energy terms only for CBS-Wes style frozen-core (the only case for which they have been determined). Corrections are only included for elements H-Ar.

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IOp(8/123)

Flag for SOS in EOM.

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Last updated on: 21 October 2016. [G16 Rev. C.01]