Turn next line into keywords 

Add another line of keywords 

Read in data, then stop 

Print final oneelectron matrix 

Do one scf and then stop 

ADDH  Add hydrogen atoms (intended for use with organic compounds) 
A0  Input geometry is in atomic units 
Read in abinitio derivatives 

Geometry must be in Gaussian format 

Print the geometry in Gaussian format in the ARC file 

ALLBONDS  Print final bondorder matrix, including bonds to hydrogen 
Print all vectors (keywords vectors also needed) 

ALT_A=A  In PDB files with alternative atoms, select atoms A 
ALT_R=A  In PDB files with alternative residues, select residues A 
ANGSTROMS  Input geometry is in Angstroms 
Symmetry to be imposed automatically 

AUX  Output auxiliary information for use by other programs 
Use the AM1 hamiltonian 

reduce bar length by a maximum of n.nn% 

Only even unit cells used (used by BZ) 

Do a maximum of n big steps 

System has two unpaired electrons 

Print final bondorder matrix 

Use CampKing converger in SCF 

Print pointgroup character table 

A multielectron configuration interaction specified 

CHAINS(text)  In a protein, explicitely define the letters of chains. 
CHECK  Report possible faults in input geometry 
Charge on system = n (e.g. NH4 = +1) 

CHARGES  Print net charge on system, and all charges in the system 
Print details of working in CHARST 

C.I. uses 1 electron excitations only 

C.I. uses 1 and electron excitations 

C.I. uses 1, 2 and 3 electron excitations 

Print heat of formation calculated in COMPFG 

COSCCH  Add in COSMO charge corrections 
Write details of the solvent accessible surface to a file 

Madelung distance cutoff is n .nn Angstroms 

CUTOFF=n.nn  In MOZYME, the interatomic distance where the NDDO approximation stops 
Do a maximum of n steps 

CVB  In MOZYME. add and remove specific bonds to allow a Lewis or PDB structure. 
DAMP=n.nn  n MOZYME. damp SCF oscillations using a factor of n.nn 
DATA=text  Input data set is redefined to text 
Print part of working in DCART 

See EF code 

Minimum trust radius in a EF/TS calculation 

Debug option turned on 

Print working in PULAY 

Density matrix output 

Print final density matrix 

Print part of working in DERI1 

Print part of working in DERI2 

Print part of working in DERIT 

Print part of working in DERIV 

Print part of working in DERNVO 

Force calculation specified, also print force matrix. 

Use DavidsonFletcherPowell method to optimize geometries 

Distance for interactions in fine grid in COSMO 

DISP  Print the hydrogen bonding and dispersion contributions to the heat of formation 
Maximum stepsize in eigenvector following 

Doublet state required 

Dynamic reaction coordinate calculation 

Write restart files every n seconds 

Data are echoed back before calculation starts 

Use ef routine for minimum search 

EIGEN  Print canonical eigenvectors instead of LMOs in MOZYME calculations 
Print all eigenvalues in ITER 

Partition energy into components 

Dielectric constant in COSMO calculation 

Electrostatic potential calculation 

Restart of electrostatic potential 

Calculate RHF spin density 

Optimize first excited singlet state 

Read parameters off disk 

An external electric field is to be used 

In RHF open and closed shell, force M.O. n to be filled 

Print details of geometry optimization 

Print details of working in FMAT 

Print last Fock matrix 

Print symmetrized Hessian in a FORCE calculation 

Calculate vibrational frequencies 

Override some safety checks 

GEO_DAT=<text>  Read in geometry from the file <text> 
GEO_REF=<text>  Read in a second geometry from the file <text> 
Exit when gradient norm drops below n .n kcal/mol/Angstrom 

Print all gradients 

Generate unformatted file for graphics 

Generate formatted file for graphics suitable for Jmol and MOPETE. 

HCORE  Print all parameters used, the oneelectron matrix, and twoelectron integrals 
HESSIAN  Print Hessian from geometry optimization 
Options for calculating Hessian matrices in EF 

Heat of formation takes priority in DRC 

HTML  Write a webpage for displaying and editing a protein 
Hyperfine coupling constants to be calculated 

Make all coordinates internal coordinates 

INVERT  Reverse all optimization flags 
IONIZE  Do not use  use SITE=(IONIZE) instead 
Intrinsic reaction coordinate calculation 

Force matrix written to disk (channel 9 ) 

Print details of working in ITER 

Set limit of number of SCF iterations to n 

Mode of Hessian update in eigenvector following 

Excess kinetic energy added to DRC calculation 

Use CampKing converger for SCF 

Print expanded output 

LBFGS  Use the lowmemory version of the BFGS optimizer 
Override certain safety checks 

LEWIS  Print the Lewis structure 
Print details of line minimization 

Print localized orbitals. These are also called Natural Bond Orbitals or NBO 

LOCATETS  Given reactants and products, locate the transition state connecting them 
LOG  Generate a log file 
Print details of MECI calculation 

Keyword generated by MAKPOL for use with program BZ 

METAL=(a[,b[,c[...]]])  Make specified atoms 100% ionic 
Use specific microstates in the C.I. 

MINI  Reduce the size of the output by only printing specified atoms 
Minimize MEP minima in the plane defined 

Use molecular mechanics correction to CONH bonds 

Use the MNDO hamiltonian 

Use the MNDOd hamiltonian 

In EF, follow Hessian mode no. n 

MOL_QMMM  Incorporate environmental effects in the QM/MM approach 
Print details of working in MOLDAT 

Print details of working in MOLSYM 

Use old MOPAC definition for 2nd and 3rd atoms 

MOZYME  Use the Localized Molecular Orbital method to speed up the SCF 
In MECI, magnetic component of spin 

Print the Mulliken population analysis 

In excited state COSMO calculations, set the value of N**2 

Minimize gradients using NLLSQ 

Do not use analytical C.I. derivatives 

NOGPU  Do not use GPU acceleration 
Suppress log file trail, where possible 

Do not use molecular mechanics correction to CONH bonds 

NONET state required 

Do not use NewtonRaphson method in EF 

Do not optimize the coordinates of all atoms of type X 

In symmetry work, use supplied orientation 

Suppress the default resequencing of atoms to the PDB sequence 

NOSWAP  Do not allow atom swapping when GEO_REF is used 
Pointgroup symmetry set to C1 

Do not put "TER"s in PDB files 

Do not use Thiel's FSTMIN technique 

Remove any text from atom symbols 

Do not print Cartesian coordinates 

Sets number of geometric segments in COSMO 

Number of surfaces in an ESP calculation 

Octet state required 

In COSMO, use the old Solvent Accessible Surface calculation 

Read initial density matrix off disk 

Use the old fundamental physical constants 

Previous geometry to be used 

In TS, minimum allowed overlap of eigenvectors 

Openshell UHF or RHF calculation requested 

Optimize the coordinates of all atoms of type X 

OPT(text=n.nn)  Optimize coordinates of all atoms within n.nn Ångstroms of atoms labeled "text" 
OUTPUT  Reduce the amount of output (useful for large systems) 
An applied pressure of n.nn Newtons/m^{2 }to be used 

PDB 
Input geometry is in protein data bank format 
PDB=(text) 
User defined chemical symbols in protein data base 
PDBOUT 
Output geometry in pdb format 
C.I. involves paired excitations only 

Resolve density matrix into σ, π, and δ components 

pKa  Print the pKa for ionizable hydrogen atoms attached to oxygen atoms 
Monitor convergence of density matrix in ITER 

Use the MNDOPM3 Hamiltonian 

Use the PM6 Hamiltonian 

PM6D3  Use the PM6 Hamiltonian with Grimme's corrections for dispersion 
PM6DH+  Use the PM6 Hamiltonian with corrections for dispersion and hydrogenbonding 
PM6DH2  Use the PM6 Hamiltonian with corrections for dispersion and hydrogenbonding 
PM6DH2X  Use PM6 with corrections for dispersion and hydrogen and halogen bonding 
PM6D3H4  Use PM6 with Řezáč and Hobza's D3H4 correction 
PM6D3H4X  Use PM6 with Brahmkshatriya, et al.'s D3H4X correction 
Complete semiempirical MEP calculation 

Use the PM7 Hamiltonian  
PM7TS  Use the PM7TS Hamiltonian (only for barrier heights) 
Complete semiempirical MEP in a plane to be defined 

Number of points in reaction path 

Number of points in first direction in grid calculation 

Number of points in second direction in grid calculation 

Calculate first, second and third order polarizabilities 

In ESP, write out electrostatic potential to unit 21 

Print details of working in POWSQ 

Criteria to be increased by 100 times 

PRESSURE  Apply pressure or tension to a solid or polymer 
Print details of geometry optimization in EF 

PRTCHAR  Print charges in ARC file 
Print interatomic distances 

MEP contour data output to <filename>.mep 

PRTXYZ  Print Cartesian coordinates 
Use Pulay's converger to obtain a SCF 

QMMM  Incorporate environmental effects in the QM/MM approach 
Charges derived from WangFord type AM1 MEP 

Quartet state required 

Quintet state required 

RAPID  In MOZYME geometry optimizations, only use atoms being optimized in the SCF 
In EF, recalculate Hessian every n steps 

RELOCAL, RELOCAL=n  During and at end of MOZYME calculation, relocalize the LMOs 
Default SCF criterion multiplied by n 

REORTHOG  In MOZYME, reorthogonalize LMO's each 10 SCF calculations. 
RESEQ  Rearrange the atoms to match the PDB convention 
RESIDUES  Label each atom in a polypeptide with the amino acid residue 
Calculation restarted 

RHF  Use Restricted HartreeFock methods 
RM1  Use the RM1 Hamiltonian 
In TS, maximum allowed ratio for energy change 

In TS, minimum allowed ratio for energy change 

Root n to be optimized in a C.I. calculation 

In EF, scale pRFO to trust radius 

Effective radius of solvent in COSMO 

Optimize transition state 

Scaling factor for van der waals distance in ESP 

Default SCF criterion replaced by the value supplied 

Increment between layers in ESP 

Septet state required 

SETPI  In MOZYME, some π bonds are explicitly set by the user 
Extra keywords to be read from setup file 

Sextet state required 

a damping factor of n defined to start SCF 

SHUT <file>  Send a command to MOPAC to make a restart and density file, then stop. 
Minimize gradients using SIGMA 

Singlet state required 

SITE=(text)  Define ionization state of residues in proteins 
In LBFGS optimization, use fixed step of length n .nn 

Multiplier used to scale MNDO charges 

SMOOTH  In a GRID calculation, remove artifacts caused by the order in which points are calculated 
Increase precision of symmetry angles 

SPARKLE  Use sparkles instead of atoms with basis sets 
Print final UHF spin matrix 

START_RES(text)  Define starting residue numbers in a protein, if different from the default 
Calculate Polarizability using electric fields 

Step size in path 

Step size n for first coordinate in grid calculation 

Step size n for second coordinate in grid calculation 

Deorthogonalize orbitals in STO3G basis 

Print superdelocalizabilities 

Output a file for use by Tripos's SYBYL program 

Average symmetry equivalent ESP charges 

Print characters of eigenvectors and print number of I.R.s 

Print details of working in subroutine SYMTRZ. 

Impose symmetry conditions 

A time of n seconds requested 

Perform a thermodynamics calculation 

THREADS=n  Set the number of threads to be used in parallelization to n 
Print times of various stages 

Time takes priority in DRC 

The system is a transition state (used in thermodynamics calculation) 

Triplet state required 

Using EF routine for TS search 

Use the Unrestricted HartreeFock method 

Van der waals radius for atoms in COSMO defined by user 

VDWM(text)  Van der waals radius for atoms in MOZYME defined by user 
Print final eigenvectors 

Supply the initial velocity vector in a DRC calculation 

Use Williams surface 

Geometry changes take priority in DRC 

XENO  Allow nonstandard residues in proteins to be labeled. 
Do all geometric operations in Cartesian coordinates 

Z=n  Number of mers in a cluster 