Chapter 6. Keywords

Chapter 6. Keywords
	Part I. AMPAC™ 10 User Guide

Table of Contents

Topical List of Major Keywords Used in AMPAC™

General Controls
Output Controls
Restart
Methods
SCF Convergence
Geometry Optimization
Sparse Matrix Keywords
Transition State Location
Properties
Population Analysis
Configuration Interaction / Spin State
Electrostatic Potential
Annealing
Eigenvector Following
Solvation
Dispersion and Hydrogen Bonding Corrections
Compatibility

Alphabetical List of Major Keywords Used in AMPAC™

#
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
S
T
U
V
W
X

Specification of Keywords

Keywords are used to define the type of calculation to be carried out. They are specified starting on the first line of the input file and may be spread over multiple lines. If more than one line of keywords is used, all but the final one must be terminated with a “+”. The only limitation is that the total length of the keywords must not exceed 512 characters. Most keywords may be abbreviated and the acceptable abbreviations are found in the description of each keyword that follows.

Note that if a keyword is misspelled or a keyword is used that AMPAC™ does not recognize, AMPAC will ignore it and no error message will be generated. The top of the output file should be checked if there is any doubt about which keywords were recognized by AMPAC, as they are echoed here. Keywords specific to specialized modules are listed in the Chapters describing those modules.

Topical List of Major Keywords Used in AMPAC™

General Controls

0SCF	Read in data, then stop.
1SCF	Do 1 SCF calculation and then stop.
ALLOWATOMS	Set maximum number of atoms allowed in calculation.
CHARGE	Define the charge on the system.
GEO-OK	Override interatomic distance check.
IADM	Interatomic Distance Matrix will be printed.
LET	Do not reduce gradients in FORCE.
LICENSE	Output information on your AMPAC™ license.
NOARC	Suppress output of the `.arc` file.
NOOUT	Suppress output of the `.out` file.
NOREF	Elemental parameter set references will not be printed.
NOVIS	Suppress output of the `.vis` file.
NOXYZ	Suppress output of Cartesian coordinates.
NPROC	Set number of processors to use during the calculation (if supported).
OPTMAX	Set the maximum number of geometry optimization cycles.
PRINT	Set verbosity of output.
RHF	Spin-restricted Hartree-Fock calculation.
ROHF	Restricted open-shell Hartree–Fock calculation.
SCFLOCAL	Localized MOs are produced by the SCF procedure.
SYMMETRY	Symmetry conditions will be imposed.
T	Define time limit for calculation.
UHF	Spin-unrestricted Hartree-Fock calculation.
VIS=MIN	Reduce the output in the `.vis` file.
XYZ	Optimization to proceed in Cartesian space.

Output Controls

Enhanced Output

Keywords in this category affect the information contained within the AMPAC output file.

1ELECTRON	Final one-electron matrix will be printed.
ALLVEC	All atomic orbital contributions to the MOs will be printed.
AMSPRNT	Set level of AMSOL printout.
BONDS	Print only non-zero elements of final two-center bond order matrix.
COMPFG	Print heat of formation calculated in the COMPFG subroutine.
CONTRIB	Print list of external contributors.
DEBUG	Turn on additional debug output.
DEGEN	Print warnings if degenerices in HOMO.
DENSITY	Final density matrix will be printed.
EIGS	Print out HF eigenvalues at every step of the SCF procedure.
ENPART	Energy will be partitioned into components.
FOCK	Final Fock matrix will be printed.
GRADIENTS	All gradient components and the gnorm will be printed.
INERTIAL	Cartesian force constants are output in the inertial frame.
LOCALIZE	Localized orbitals will be printed.
OPTPRT	Monitor convergence of geometry optimization.
OVERLAP	Overlap matrix will be printed.
PI	Resolve density matrix into sigma and pi bonds.
PRINT	Set verbosity of output.
PRINTHESSIAN	Final Hessian matrix will be printed.
SCFPRT	Monitor convergence in self-consistent field procedure.
SPIN	Final UHF spin matrix will be printed.
TIMES	Print timings at various stages of the calculation.
VECTORS	Selected atomic orbital contributions to the MOs will be printed.

Special Output

Keywords in this category produce special output files with unique filename extensions.

COSMOWRT	Write out data for further COSMO processing.
DENMAT	Density matrix will be written to disk in ASCII format.
DENOUT	Density matrix will be written to disk in binary format.
GRAPH	Write out data for graphics in binary format.
POTWRT	Dump out the surface points and electrostatic potential values.
SYBYL	Output information for input into Sybyl.

Restart

DENMAT	Density matrix will be written to disk in ASCII format.
DENOUT	Density matrix will be written to disk in binary format.
OLDENS	Initial density matrix read from binary file.
OLDMAT	Initial density matrix read from ASCII file.
RESTART	Calculation will be restarted using results from disk.

Methods

AM1	The AM1 Hamiltonian will be used.
AM1-D3H4	Use AM1 Hamiltonian plus D3H4 dispersion and hydorgen-bond corrections.
AM1-FS2	Use AM1 Hamiltonian plus AM1-FS2 dispersion and hydorgen-bond corrections.
MINDO3	The MINDO3 Hamiltonian will be used.
MNDO	The MNDO Hamiltonian will be used.
MNDOC	The MNDOC Hamiltonian will be used.
MNDOD	The MNDO/d Hamiltonian will be used.
PM3	The PM3 Hamiltonian will be used.
PM3-D3H4	Use PM3 Hamiltonian plus D3H4 dispersion and hydorgen-bond corrections.
PM6	The PM6 Hamiltonian will be used.
PM6-D3H4	Use PM6 Hamiltonian plus D3H4 dispersion and hydorgen-bond corrections.
RM1	The RM1 Hamiltonian will be used.
RM1-D3H4	Use RM1 Hamiltonian plus D3H4 dispersion and hydorgen-bond corrections.
SAM1	The SAM1 Hamiltonian will be used.
SAM1D	The SAM1 Hamiltonian, with d-orbitals on I and Cl, will be used.

SCF Convergence

0SCF	Read in data, then stop.
1SCF	Do 1 SCF calculation and then stop.
NEWDEN	Always start SCF with a new guess density.
QCSCF	Explicitly invoke quadratically convergent SCF procedure.
SCFBOOST	Additional cycles for final convergence of wavefunction.
SCFCRT	SCF termination criteria computed based on specified value.
SCFMAX	Set limit on number of SCF iterations to specified value.

Geometry Optimization

BFGS	Use BFGS method in geometry optimization.
DERINU	Derivatives will be computed numerically.
DFP	Use Davidon-Fletcher-Powell rather than BFGS in geometry optimization.
EF	Use the eigenvector following method to locate a minimum.
GNORM	Exit geometry optimizations when gradient norm falls below a specified value.
GRADIENTS	All gradient components and the gnorm will be printed.
LINDH	Use Lindh’s method for initial guess for Hessian matrix.
LTRD	Minimize gradient using full Hessian.
NEWTON	Minimize energy using full Hessian.
TRUSTE	Default method for geometry optimization using trust radii.
TRUSTG	Default method for gradient minimization using trust radii.

Sparse Matrix Keywords

CGDIIS	Use DIIS during conjugate-gradient steps.
DIRECTSCF	Don’t store two electron integrals.
ENHANCE	Supplement the matrix form used in sparse PSOLVE with additional elements.
FLETCHER	Use Fletcher-Reeves version of conjugate gradient.
FULLCNV	Fully converge conjugate gradient at each SCF cycle.
GERSH	Use Gershgorin method to compute bounds on the Fock matrix eigenvalues.
LEWIS	Generate initial guess based on Lewis dot structure analysis.
NOHL	Avoid computation of the HOMO-LUMO orbitals and gap.
NOPRECON	Do not use preconditioning during conjugate gradient.
PCONV	Set the convergence criteria for PSOLVE=CGDMS or QNDMS.
PRTLWS	Set level of output during LEWIS.
PSOLVE	Set the sparse matrix solver method.
PSPRT	Set level of output during PSOLVE and sparse matrix operations.
SCFDIIS	Use DIIS to improve convergence of the SCF.
SPARSE	Perform sparse matrix calculation using the specified neglect threshold.
VSHIFT	Set level shift during CGDMS or QNDMS.

Transition State Location

GRID	Specify dimensions for a 2D reaction grid calculation.
HMIN	Minimum allowed step length for IRC/Path.
IRC	Follow the intrinsic reaction coordinate.
PATH	Follow the descending reaction path.
STEP1	Specify step size for first coordinate in reaction grid calculation.
STEP2	Specify step size for second coordinate in reaction grid calculation.
TS	Use the eigenvector following method to locate a transition state.
T.V.	A transition vector is provided for IRC or PATH.
WEIGHT	Weights for T.V. components will be provided for PATH.

CHN Methods

(See Chapter 8, CHN Methods.)

CATCHTS	Define the neglect threshold for low-energy extrema during FULLCHN jobs.
CHAIN	Find transition state using CHAIN method.
CHECKCHN	Build trial path for CHN only.
CHN	Locate limitant transition state along CHN path.
DISSOC	Define the dissociation threshold for CHN methods.
FULLCHN	Locate transition state(s) and intermediate point(s) along CHN path.
MAXNOD	Maximum number of nodes in a CHAIN/CHN calculation.
MAXQUE	Size of queue to store candidates in simulated annealing calculation.
OPTIL	Optimize left (reactant) starting geometry.
OPTILR	Optimize both the left (reactant) and right (product) starting geometries.
OPTIR	Optimize right (product) starting geometry.
OPTIRL	Optimize both the right (product) and left (reactant) starting geometries.

Properties

APOLAR	Compute nonlinear optical properties using analytic gradient.
BRUTEKPOLAR	Use Kurtz’s method for computing nonlinear optical properties in the genuine Cartesian frame.
ESR	Unpaired spin density on atoms will be calculated.
FORCE	Force calculation for a Cartesian frequency analysis requested.
HESSEI	Compute a few lowest Hessian eigenvalues.
HESSIAN2	Force 2-point formula to compute Hessian.
HESSIAN4	Force 4-point formula to compute Hessian.
HYPERFINE	Computes hyperfine coupling constants for a UHF calculation.
INERTIAL	Cartesian force constants are output in the inertial frame.
ISOTOPE	Final force matrix written to disk.
KPOLAR	Use Kurtz’s method for computing nonlinear optical properties in the inertial frame.
LFORCE	Compute the IR spectrum for a few lowest frequencies.
MPG	Find molecular point groups and list tolerances.
MPGCRT	Use specified value as tolerance to compute molecular point group.
ROT	Defines rotational symmetry.
SPIN	Final UHF spin matrix will be printed.
STEPHESS	Specify step size in numerical differentiation of Hessian.
THERMO	Set the temperature range for calculating thermodynamic properties.
TRANS	Deletes the n lowest vibrations in a THERMO calculation.

Population Analysis

ESP	Invokes the electrostatic potential method for charge calculation.
MULLIKEN	Perform a pseudo-Mulliken population analysis.
NBO	Perform natrual bond orbital (NBO) analysis.

Configuration Interaction / Spin State

(See Chapter 11, Configuration Interaction.)

AVEPMO	Averaged density matrix in MO basis for the first `n` eigenstates.
BIRADICAL	System has two unpaired electrons.
C.I.	Include `n` orbitals around the HOMO in the CI manifold.
CI-OK	Override degeneracy check.
CIDIP	Calculate charges and dipole moments for CI eigenstates.
CIGAP	Specify energy gap used to determine microstate degeneracy.
CIMAX	Specify the maximum number of microstates.
CIOUT	Write details about the CI eigenstates to file.
CISTATE	Specify the number of final CI eigenstates to be calculated and printed.
CITRANS	Outputs the transition dipole information between all states.
DAVDBG	Write details about the CI matrix diagonalization to file.
DECET	RHF decet state required.
DOUBLET	RHF doublet state required.
DYNPOL	Outputs data for dynamic polarizability calculations.
EXCITED	First excited singlet state will be optimized.
FILL	Require use of defined set of prototype MOs.
INCI	Read final microstates from an ASCII file.
JKPRINT	All unique two electron integrals over CI-active MOs written to output file.
MATCI	Energies and AO coefficients of CI-active MOs printed to output file.
MECI	Print information about CI microstates and transitions.
MICROS	Generates only microstates with spin = `n`.
MSCHARG	Maximum charge for generated microstates.
`n`-ET	Constrains the spin multiplicity of the primary CI eigenstate to be `n`.
NONET	RHF nonet state required.
OCI	Expand space of single excitations in a CI calculation.
OCTET	RHF octet state required.
OPEN	Configuration Interaction.
PERTU	Override the default perturbative selection of microstates.
PROTO	Define prototype MOs.
QUARTET	RHF quartet state required.
QUINTET	RHF quintet state required.
RECLAS	Reorder MOs.
RIGIDCI	Propagate initial selection of microstates throughout a geometry optimization.
ROOT	Specify spin state to follow.
SCFCI	Defines two sets of open-shell MOs and their fractional occupancies to be used in a “half-electron” RHF SCF calculation preceding a CI calculation.
SC.I.	Specify CI-active MOs in a S-CI calculation.
SDC.I.	Specify CI-active MOs in a SD-CI calculation.
SDTC.I.	Specify CI-active MOs in a SDT-CI calculation.
SEPS	Specify energy gap used to determine eigenstate degeneracy.
SINGLET	RHF singlet state required.
SEPTET	RHF septet state required.
SEXTET	RHF sextet state required.
SZ	Specify value of S_z.
TRIPLET	Triplet state required.
VALIDCI	Indicate that the microstates to be read in are fully consistent.

Electrostatic Potential

(See Chapter 10, Electrostatic Potential)

CONNOLLY	Enable use of the Connolly surface for the ESP calculation.
DEN	Specify a different point density for the Connolly surface.
DIPOLE	Constrain the ESP dipole moment as predicted by AMPAC’s Coulson analysis.
DIPX	Specify the x-component of the dipole moment.
DIPY	Specify the y-component of the dipole moment.
DIPZ	Specify the z-component of the dipole moment.
NSURF	Change the number of surfaces used in the Connolly algorithm.
POTWRT	Dump out the surface points and electrostatic potential values.
SCALE	Change the base scaling factor in the Connolly treatment.
SCINCR	Specify the increment between multipliers for the Connolly surface.
SLOPE	Change the scaling factor when using MNDO ESP charges.
STO3G	Specify basis set to “deorthogonalize” the semiempirical density matrix.
STO6G	Specify basis set to “deorthogonalize” the semiempirical density matrix.
SYMAVG	Average charges which should have the same value by symmetry.
WILLIAMS	Specify surface generation procedure of Donald Williams.

Annealing

(See Chapter 13, Simulated Annealing.)

ANNEAL	Simulated annealing search for geometric minima.
AUTOLIMIT	Define default preliminary periodic boundaries.
BPFREF	Define central value of the band-pass filter.
BPFSIG	Define half-width of the band-pass filter.
CRUDE	Use crude rejection scheme.
FCTOR3	Determine balance between energy and gnorm (MANNEAL only).
FILTER	Determine equivalency of configurations during the clustering sort.
FREF	Define central value of the energy range.
GANNEAL	Simulated annealing search for extrema within an energy range.
GAUSSIAN	Use a Gaussian, rather than uniform, random number generator for geometry displacement.
LIMIT	Define periodic boundaries.
LTRD	Minimize gradient using full Hessian.
MANNEAL	Simulated annealing search for minima within an energy range.
MARK	All points of the Markov chains are written to channel 8.
NCHECK	Define interval for producing quenching candidates at each temperature.
NEWTON	Minimize energy using full Hessian.
NMAX	Define maximum value of criterion calls at a given temperature.
NOQUENCH	Skip quenching.
NRAND	Define random number seed value.
PENA	Activate penalty function on the molecule’s moments of inertia.
PEN1	Activate close contact penalty function.
PEN2	Activate conformational penalty function.
PEN2GRP	Activate conformational penalty function within distinct groups.
PREF	Define the energy window penalty coefficient.
SREF	Specify half-width of the searched energy range.
STD	Define thermalization criterion.
STEP	Define maximum step size in the annealing search.
STEPCV	Define a lower bound for the step size (% of initial step).
TEMP	Starting “temperature” for the annealing procedure.
TEST	Print extra debugging output.
TLAW	Specify the decay constant in the temperature.
TOL	Permitted relative variation of a bond length from its initial value.
TSANNEAL	Simulated annealing search for extrema within an energy range.
WHOLE	End the quenching steps will full optimizations.

Eigenvector Following

(See Chapter 9, Eigenvector Following )

DDMAX	Define the maximum size of the trust radius.
DDMIN	Define the minimum size of the trust radius.
DMAX	Define the initial trust radius.
GNMIN	Activate gradient test for accepting geometry steps.
HESS	Specify the source of the Hessian matrix.
IUPD	Choice of update method for the Hessian matrix.
MODE	Specify eigenvector to follow during optimization.
NONR	Specify P-RFO method for geometry projection.
NOUPD	Suppress updating of the trust radius at Stage 3.
OMIN	Specify minimum overlap between successive TS search vectors.
RECALC	Specify interval (in number of steps) for Hessian recalculation.
RMAX	Adjust maximum criterion for accepting geometry steps.
RMIN	Adjust minimum criterion for accepting geometry steps.
RSCAL	Scale the P-RFO step.

Solvation

COSMO

(See Chapter 14, COSMO Solvation Model.)

COSMO	Invoke the COSMO solvation model.
COSMOWRT	Write out data for further COSMO processing.
DELSC	Specify the effective molecular radius of the desired solvent.
DIELEC	Specify the dielectric constant for desired solvent. (Equivalent to EPS)
DISEX	Distance threshold for using two-point interaction approximation.
EPS	Specify the dielectric constant for desired solvent. (Equivalent to DIELEC)
IOFR	Specify the index of refraction of the desired solvent. (Equivalent to REFRACT)
NSPA	Specify the number of segments per atom.
OLDCMMINDO	Use old MINDO3 parameters with COSMO.
REFRACT	Specify the index of refraction of the desired solvent. (Equivalent to IOFR)
RSOLV	Specify the molecular radius of the desired solvent.
VDW	Specify an element’s van der Waals radius.

AMSOL

(See Chapter 15, AMSOL Model Module.)

ALPHA	Specify alpha of the desired solvent.
AMSPRNT	Set level of AMSOL printout.
BETA	Specify beta of the desired solvent.
DELSC	Specify the effective molecular radius of the desired solvent.
DIELEC	Specify the dielectric constant for desired solvent. (Equivalent to EPS)
DISEX	Distance threshold for using two-point interaction approximation.
EPS	Specify the dielectric constant for desired solvent. (Equivalent to DIELEC)
FACARB	Specify the fraction of non-hydrogenic solvent atoms that are carbon atoms contained in an aromatic ring.
FEHALO	Specify the fraction of non-hydrogenic solvent atoms that are electronegative halogen atoms.
GAMMA	Specify the macroscopic surface tension of the desired solvent.
HGAS	Specify the heat of formation (kcal/mol) of the solute in the gas phase.
IOFR	Specify the index of refraction of the desired solvent. (Equivalent to REFRACT)
NOPOL	Polarization energy computed with gas phase solvent wavefunction.
NSPA	Specify the number of segments per atom.
REFRACT	Specify the index of refraction of the desired solvent. (Equivalent to IOFR)
RSOLV	Specify the molecular radius of the desired solvent.
SM5.2	Request a calculation using the SM5.2 model.
SM5.2R	Request a calculation using the SM5.2R model.
SM5C	Request a calculation using the SM5C model.
SM5CR	Request a calculation using the SM5CR model.
SOLVNT	Indicate which parameter set will be used in the SM5 calculation.
TEXPN	Solvation trapezoidal integration shell growth factor.
TONE	Solvation trapezoidal integration shell thickness.
TRUES	Calculate the true solvation free energy.
VDW	Specify an element’s van der Waals radius.

Dispersion and Hydrogen Bonding Corrections

AM1-D3H4	Use AM1 Hamiltonian plus D3H4 dispersion and hydorgen-bond corrections.
AM1-FS2	Use AM1 Hamiltonian plus AM1-FS2 dispersion and hydorgen-bond corrections.
PM3-D3H4	Use PM3 Hamiltonian plus D3H4 dispersion and hydorgen-bond corrections.
PM6-D3H4	Use PM6 Hamiltonian plus D3H4 dispersion and hydorgen-bond corrections.
RM1-D3H4	Use RM1 Hamiltonian plus D3H4 dispersion and hydorgen-bond corrections.

Compatibility

CODESSA™

CODESSA

Generate output options for CODESSA™

SYBYL®

SYBYL

Output information for input into SYBYL®.

Alphabetical List of Major Keywords Used in AMPAC™

#

0SCF	Read in data, then stop.
1ELECTRON	Final one-electron matrix will be printed.
1SCF	Do 1 SCF calculation and then stop.

A

ALLOWATOMS	Set maximum number of atoms allowed in calculation.
ALLVEC	All atomic orbital contributions to the MOs will be printed.
ALPHA	Specify alpha of the desired solvent.
AM1	The AM1 Hamiltonian will be used.
AM1-D3H4	Use AM1 Hamiltonian plus D3H4 dispersion and hydorgen-bond corrections.
AM1-FS2	Use AM1 Hamiltonian plus AM1-FS2 dispersion and hydorgen-bond corrections.
AMSPRNT	Set level of AMSOL printout.
ANNEAL	Simulated annealing search for geometric minima.
APOLAR	Compute nonlinear optical properties using analytic gradient.
AUTOLIMIT	Define default preliminary periodic boundaries.
AVEPMO	Averaged density matrix in MO basis for the first `n` eigenstates.

B

BETA	Specify beta of the desired solvent.
BFGS	Use BFGS method in geometry optimization.
BIRADICAL	System has two unpaired electrons.
BONDS	Print only non-zero elements of final two-center bond order matrix.
BPFREF	Define central value of the band-pass filter.
BPFSIG	Define half-width of the band-pass filter.
BRUTEKPOLAR	Use Kurtz’s method for computing nonlinear optical properties in the genuine Cartesian frame.

C

CATCHTS	Define the neglect threshold for low-energy extrema during FULLCHN jobs.
CGDIIS	Use DIIS during conjugate-gradient steps.
CHAIN	Find transition state using CHAIN method.
CHARGE	Define the charge on the system.
CHECKCHN	Build trial path for CHN only.
CHN	Locate limitant transition state along CHN path.
C.I.	Include n orbitals around the HOMO in the CI manifold.
CI-OK	Override degeneracy check.
CIDIP	Calculate charges and dipole moments for CI eigenstates.
CIGAP	Specify energy gap used to determine degeneracy.
CIMAX	Specify the maximum number of microstates.
CIOUT	Write details about the CI eigenstates to file.
CISTATE	Specify the number of final CI eigenstates to be calculated and printed.
CITRANS	Outputs the transition dipole information between all states.
CODESSA	Generate output options for CODESSA™
COMPFG	Print heat of formation calculated in the COMPFG subroutine.
CONNOLLY	Enable use of the Connolly surface for the ESP calculation.
CONTRIB	Print list of external contributors.
COSMO	Invoke the COSMO solvation model.
COSMOWRT	Write out data for further COSMO processing.
CRUDE	Use crude rejection scheme.
CU-OLDSAM1	Use old parameters for element Cu with SAM1.

D

DAVDBG	Write details about the CI matrix diagonalization to file.
DDMAX	Define the maximum size of the trust radius.
DDMIN	Define the minimum size of the trust radius.
DEBUG	Turn on additional debug output.
DECET	RHF decet state required.
DEGEN	Print warnings if degenerices in HOMO.
DELSC	Specify the effective molecular radius of the desired solvent.
DEN	Specify a different point density for the Connolly surface.
DENMAT	Density matrix will be written to disk in ASCII format.
DENOUT	Density matrix will be written to disk in binary format.
DENSITY	Final density matrix will be printed.
DERINU	Derivatives will be computed numerically.
DFP	Use Davidon-Fletcher-Powell in geometry optimization.
DIELEC	Specify the dielectric constant for desired solvent. (Equivalent to EPS)
DIPOLE	Constrain the ESP dipole moment as predicted by AMPAC’s Coulson analysis.
DIPX	Specify the x-component of the dipole moment.
DIPY	Specify the y-component of the dipole moment.
DIPZ	Specify the z-component of the dipole moment.
DIRECTSCF	Don’t store two electron integrals.
DISEX	Distance threshold for using two-point interaction approximation.
DISSOC	Define the dissociation threshold for CHN methods.
DMAX	Define the initial trust radius.
DOUBLET	RHF doublet state required.
DYNPOL	Outputs data for dynamic polarizability calculations.

E

EF	Use the eigenvector following method to locate a minimum.
EIGS	Print out HF eigenvalues at every step of the SCF procedure.
ENHANCE	Supplement the matrix form used in sparse PSOLVE with additional elements.
ENPART	Energy will be partitioned into components.
EPS	Specify the dielectric constant for desired solvent. (Equivalent to DIELEC)
ESP	Invokes the electrostatic potential method for charge calculation.
ESR	Unpaired spin density on atoms will be calculated.
EXCITED	First excited singlet state will be optimized.

F

FACARB	Specify the fraction of non-hydrogenic solvent atoms that are carbon atoms contained in an aromatic ring.
FCTOR3	Determine balance between energy and gnorm (MANNEAL only).
FEHALO	Specify the fraction of non-hydrogenic solvent atoms that are electronegative halogen atoms.
FILL	Require use of defined set of prototype MOs.
FILTER	Determine equivalency of configurations during the clustering sort.
FLETCHER	Use Fletcher-Reeves version of conjugate gradient.
FOCK	Final Fock matrix will be printed.
FORCE	Force calculation for a Cartesian frequency analysis requested.
FREF	Define central value of the energy range.
FULLCHN	Locate transition state(s) and intermediate point(s) along CHN path.
FULLCNV	Fully converge conjugate gradient at each SCF cycle.

G

GAMMA	Specify the macroscopic surface tension of the desired solvent.
GANNEAL	Simulated annealing search for extrema within an energy range.
GAUSSIAN	Use a Gaussian, rather than uniform, random number generator for geometry displacement.
GEO-OK	Override interatomic distance check.
GERSH	Use Gershgorin method to compute bounds on the Fock matrix eigenvalues.
GNMIN	Activate gradient test for accepting geometry steps.
GNORM	Exit geometry optimizations when gradient norm falls below a specified value.
GRADIENTS	All gradient components and the gnorm will be printed.
GRAPH	Write out data for graphics in binary format.
GRID	Specify dimensions for a 2D reaction grid calculation.

H

HESS	Specify the source of the Hessian matrix.
HESSEI	Compute a few lowest Hessian eigenvalues.
HESSIAN2	Force 2-point formula to compute Hessian.
HESSIAN4	Force 4-point formula to compute Hessian.
HGAS	Specify the heat of formation (kcal/mol) of the solute in the gas phase.
HMIN	Minimum allowed step length for IRC/Path.
HYPERFINE	Computes hyperfine coupling constants for a UHF calculation.

I

IADM	Interatomic Distance Matrix will be printed.
INCI	Read final microstates from an ASCII file.
INERTIAL	Cartesian force constants are output in the inertial frame..
IOFR	Specify the index of refraction of the desired solvent. (Equivalent to REFRACT)
IRC	Follow the intrinsic reaction coordinate.
ISOTOPE	Final force matrix written to disk.
IUPD	Choice of update method for the Hessian matrix.

J

JKPRINT

All unique two electron integrals over CI-active MOs written to output file.

K

KPOLAR

Use Kurtz’s method for computing nonlinear optical properties in the inertial frame.

L

LET	Do not reduce gradients in FORCE.
LEWIS	Generate initial guess based on Lewis dot structure analysis.
LFORCE	Compute the IR spectrum for a few lowest frequencies.
LICENSE	Output information on your AMPAC™ license.
LIMIT	Define periodic boundaries.
LINDH	Use Lindh’s method for initial guess for Hessian matrix.
LOCALIZE	Localized orbitals will be printed.
LTRD	Minimize gradient using full Hessian.

M

MANNEAL	Simulated annealing search for minima within an energy range.
MARK	All points of the Markov chains are written to channel 8.
MATCI	Energies and AO coefficients of CI-active MOs printed to output file.
MAXNOD	Maximum number of nodes in a CHAIN/CHN calculation.
MAXQUE	Size of queue to store candidates in simulated annealing calculation.
MECI	Print information about CI microstates and transitions.
MICROS	Generates only microstates with spin = `n`.
MINDO3	The MINDO3 Hamiltonian will be used.
MNDO	The MNDO Hamiltonian will be used.
MNDOC	The MNDOC Hamiltonian will be used.
MNDOD	The MNDO/d Hamiltonian will be used.
MODE	Specify eigenvector to follow during optimization.
MPG	Find molecular point groups and list tolerances.
MPGCRT	Use specified value as tolerance to compute molecular point group.
MSCHARG	Maximum charge for generated microstates
MULLIKEN	Perform a pseudo-Mulliken population analysis.

N

NBO	Perform natrual bond orbital (NBO) analysis.
NC-PM6	No special correction terms will be used with the PM6 Hamiltonian.
NCHECK	Define interval for producing quenching candidates at each temperature.
`n`-ET	Constrains the spin multiplicity of the primary CI eigenstate to be `n`.
NEWDEN	Always start SCF with a new guess density.
NEWTON	Minimize energy using full Hessian.
NMAX	Define maximum value of criterion calls at a given temperature.
NOARC	Suppress output of the `.arc` file.
NOHL	Avoid computation of the HOMO-LUMO orbitals and gap.
NONET	RHF nonet state required.
NONR	Specify P-RFO method for geometry projection.
NOOUT	Suppress output of the `.out` file.
NOPOL	Polarization energy computed with gas phase solvent wavefunction.
NOPRECON	Do not use preconditioning during conjugate gradient.
NOQUENCH	Skip quenching.
NOREF	Elemental parameter set references will not be printed.
NOUPD	Suppress updating of the trust radius at Stage 3.
NOVIS	Suppress output of the `.vis` file.
NOXYZ	Suppress output of Cartesian coordinates.
NPROC	Set number of processors to use during the calculation (if supported).
NRAND	Define random number seed value.
NSPA	Specify the number of segments per atom.
NSURF	Change the number of surfaces used in the Connolly algorithm.

O

OCI	Expand space of single excitations in a CI calculation.
OCTET	RHF octet state required.
OLDCMMINDO	Use old parameters for COSMO with MINDO3.
OLDENS	Initial density matrix read from binary file.
OLDMAT	Initial density matrix read from ASCII file.
OMIN	Specify minimum overlap between successive TS search vectors.
OPEN	Configuration Interaction.
OPTIL	Optimize left (reactant) starting geometry.
OPTILR	Optimize both the left (reactant) and right (product) starting geometries.
OPTIR	Optimize right (product) starting geometry.
OPTIRL	Optimize both the right (product) and left (reactant) starting geometries.
OPTMAX	Set the maximum number of geometry optimization cycles.
OPTPRT	Monitor convergence of geometry optimization.
ORIENT=ORIGINAL	Don't reorient the input geomtry.
OVERLAP	Overlap matrix will be printed.

P

PATH	Follow the descending reaction path.
PCONV	Set the convergence criteria for PSOLVE=CGDMS or QNDMS.
PEN1	Activate close contact penalty function.
PEN2	Activate conformational penalty function.
PEN2GRP	Activate conformational penalty function within distinct groups.
PENA	Activate penalty function on the molecule’s moments of inertia.
PERTU	Override the default perturbative selection of microstates.
PI	Resolve density matrix into sigma and pi bonds.
PM3	The PM3 Hamiltonian will be used.
PM3-D3H4	Use PM3 Hamiltonian plus D3H4 dispersion and hydorgen-bond corrections.
PM6	The PM6 Hamiltonian will be used.
PM6-D3H4	Use PM6 Hamiltonian plus D3H4 dispersion and hydorgen-bond corrections.
POTWRT	Dump out the surface points and electrostatic potential values.
PREF	Define the energy window penalty coefficient.
PRINT	Set verbosity of output.
PRINTHESSIAN	Final Hessian matrix will be printed.
PROTO	Define prototype MOs.
PRTLWS	Set level of output during LEWIS.
PSOLVE	Set the sparse matrix solver method.
PSPRT	Set level of output during PSOLVE and other sparse matrix operations.

Q

QCSCF	Explicitly invoke quadratically convergent SCF procedure.
QUARTET	RHF quartet state required.
QUINTET	RHF quintet state required.

R

RECALC	Specify interval (in number of steps) for Hessian recalculation.
RECLAS	Reorder MOs.
REFRACT	Define the solvent’s refractive index.
RESTART	Calculation will be restarted using results from disk.
RHF	Spin-restricted Hartree-Fock calculation.
RIGIDCI	Propagate initial selection of microstates throughout a geometry optimization.
RM1	The RM1 Hamiltonian will be used.
RM1-D3H4	Use RM1 Hamiltonian plus D3H4 dispersion and hydorgen-bond corrections.
RMAX	Adjust maximum criterion for accepting geometry steps.
RMIN	Adjust minimum criterion for accepting geometry steps.
ROHF	Restricted open-shell Hartree–Fock calculation.
ROOT	Specify spin state to follow.
ROT	Defines rotational symmetry.
RSCAL	Scale the P-RFO step.
RSOLV	Define the solvent’s molecular radius.

S

SAM1	The SAM1 Hamiltonian will be used.
SAM1D	The SAM1 Hamiltonian, with d-orbitals on I and Cl will be used.
SCALE	Change the base scaling factor in the Connolly treatment.
SCFBOOST	Additional cycles for final convergence of wavefunction.
SCFCI	Defines two sets of open-shell MOs and their fractional occupancies to be used in a “half-electron” RHF SCF calculation preceding a CI calculation.
SCFCRT	SCF termination criteria computed based on specified value.
SCFDIIS	Use DIIS to improve convergence of the SCF.
SCFLOCAL	Localized MOs are produced by the SCF procedure.
SCFMAX	Set limit on number of SCF iterations to specified value.
SCFPRT	Monitor convergence in self-consistent field procedure.
SC.I.	Specify CI-active MOs in a S-CI calculation.
SCINCR	Specify the increment between multipliers for the Connolly surface.
SDC.I.	Specify CI-active MOs in a SD-CI calculation.
SDTC.I.	Specify CI-active MOs in a SDT-CI calculation.
SEPS	Specify energy gap used to determine eigenstate degeneracy.
SEPTET	RHF septet state required.
SEXTET	RHF sextet state required.
SHOWPARAM	Show semi-empirical method parameters for each element.
SINGLET	RHF singlet state required.
SLOPE	Change the scaling factor when using MNDO ESP charges.
SM5.2	Request a calculation using the SM5.2 model.
SM5.2R	Request a calculation using the SM5.2R model.
SM5C	Request a calculation using the SM5C model.
SM5CR	Request a calculation using the SM5CR model.
SOLVNT	Indicate which parameter set will be used in the SM5 calculation.
SPARSE	Perform sparse matrix calculation using the specified neglect threshold.
SPIN	Final UHF spin matrix will be printed.
SREF	Specify half-width of the searched energy range.
STD	Define thermalization criterion.
STEP	Define maximum step size in the annealing search.
STEP1	Specify step size for first coordinate in reaction grid calculation.
STEP2	Specify step size for second coordinate in reaction grid calculation.
STEPCV	Define a lower bound for the step size (% of initial step).
STEPHESS	Specify step size in numerical differentiation of Hessian.
STO3G	Specify basis set to “deorthogonalize” the semiempirical density matrix.
STO6G	Specify basis set to “deorthogonalize” the semiempirical density matrix.
SYBYL	Output information for input into SYBYL®.
SYMAVG	Average charges which should have the same value by symmetry.
SYMMETRY	Symmetry conditions will be imposed.
SZ	Specify value of S_z.

T

T	Define time limit for calculation.
TEMP	Starting “temperature” for the annealing procedure.
TEST	Print extra debugging output.
TEXPN	Solvation trapezoidal integration shell growth factor.
THERMO	Set the temperature range for calculating thermodynamic properties.
TIMES	Print timings at various stages of the calculation.
TLAW	Specify the decay constant in the temperature.
TOL	Permitted relative variation of a bond length from its initial value.
TONE	Solvation trapezoidal integration shell thickness.
TRANS	Deletes the n lowest vibrations in a THERMO calculation.
TRIPLET	Triplet state required.
TRUES	Calculate the true solvation free energy.
TRUSTE	Default method for geometry optimization using trust radii.
TRUSTG	Default method for gradient minimization using trust radii.
TS	Use the eigenvector following method to locate a transition state.
TSANNEAL	Simulated annealing search for extrema within an energy range.
T.V.	A transition vector is provided for IRC or PATH.

U

UHF	Spin-unrestricted Hartree-Fock calculation.

V

VALIDCI	Indicate that the microstates to be read in are fully consistent.
VDW	Specify an element’s van der Waals radius.
VECTORS	Selected atomic orbital contributions to the MOs will be printed.
VSHIFT	Set level shift during CGDMS or QNDMS.
VIS=MIN	Reduce the output in the `.vis` file.

W

WEIGHT	Weights for T.V. components will be provided for PATH.
WHOLE	End the quenching steps will full optimizations.
WILLIAMS	Specify surface generation procedure of Donald Williams.

X

XYZ	Optimization to proceed in Cartesian space.


Chapter 5. Presenting Input to the Program		Chapter 7. Sparse Matrix Methods