Provided by: psi3_3.4.0-5_amd64 bug

NAME

       psi3 - master execution driver for the PSI programs

DESCRIPTION

       The program psi3 reads your input deck, determines what type of calculation you are trying
       to   perform,   and   runs   the   appropriate   programs.    psi3    reads    the    file
       /usr/local/psi3/share/psi.dat  by  default.   This  file contains macros for some standard
       calculations.  Psi is very flexible, however, and anything in  the  psi.dat  file  can  be
       overridden  by  the user.  Thus, all that is written below should be taken with a grain of
       salt.  Experimentation is the best way to learn the psi3  command,  and  nothing  that  is
       written here should be taken as gospel.  A good place to look for syntax is in the psi.dat
       file.  Hopefully this man page and the psi.dat file should tell you all you need  to  know
       to get started.

COMMAND-LINE OPTIONS

       The following command-line arguments are available:

       -i or -f
              This flag is used to specify the input file name, e.g.  psi3 -i h2o.in where h2o.in
              is the name of input file. By default, psi3 and PSI modules that it calls will look
              for input.dat .

       -o     This  flag  is  used  to  specify the output file name, e.g.  psi3 -o h2o.out where
              h2o.in is the name of output file. By default, psi3 and PSI modules that  it  calls
              will look for output.dat .

       -p     This  flag  is  used  to  specify  the PSI file prefix, e.g.  psi3 -p h2o.dzp where
              h2o.dzp is the prefix that will be used for all PSI files. By default, psi3 and PSI
              modules  that it calls will use psi for the file prefix. Hence, the checkpoint file
              is by default called psi.32 .

       --noinput or -n
              This tells psi3 driver not to run input program. This flag is useful for  scripting
              and debugging.

       --check or -c
              This  tells psi3 driver to check the input and print out the list of programs which
              would be executed. Equivalent to setting CHECK=TRUE in the input file.

       --messy or -m
              This tells psi3 driver not to run cleanup program psiclean .  Usually, the  cleanup
              program  is  invoked  via the $done macro defined in psi.dat .  This flag is useful
              for scripting and debugging.

INPUT FORMAT

       The psi3 program searches through the default keyword path (first PSI  and  then  DEFAULT)
       for the following keywords:

       JOBTYPE = string
              This  tells  the  psi3  driver  program  what  kind of calculation you want to run.
              Acceptable choices are: SP (for a single-point energy  computation),  OPT  (for  an
              optimization,  either  using gradients or energies), FREQ (for harmonic vibrational
              frequencies), FC (for force constants by finite differences of internal coordinates
              ),  SYMM_FC  (for  force  constants  by finite differences of internal coordinates,
              symmetric modes only), DISP (for a series of single-points at  different  displaced
              geometries),  DBOC  (to  compute the Diagonal Born-Oppenheimer Correction [DBOC] to
              electronic energy).  The default is SP.

       WFN = string
              This is the type of wavefunction which is ultimately desired.  As of this  writing,
              acceptable  values  for  WFN are SCF, MP2, CCSD, CCSD_T, DETCI, CASSCF, and RASSCF.
              Having WFN defined as anything else is not necessarily bad, but don't  expect  psi3
              to be able to figure out what to do.  If you have a non-standard WFN, then it would
              probably be best to provide an EXEC section (see below).  There is no default.

       REFERENCE = string
              This specifies the reference wavefunction desired.  It can be one  of  RHF  (for  a
              closed shell spin-restricted Hartree-Fock), ROHF (for an open-shell spin-restricted
              Hartree-Fock), UHF (for an open-shell spin-unrestricted  Hartree-Fock),  or  TWOCON
              (for a two configuration singlet).  The default is RHF.

       DERTYPE = string
              This  specifies the order of derivative that is to eventually be done.  The default
              is NONE.

       OPT = boolean
              Set this equal to true if you are performing a geometry optimization.  The  default
              is false.  Note: This is an old keyword which is now obsolete; it has been replaced
              by the JOBTYPE keyword.

       NOPT = integer
              This gives the maximum number of iterations if OPT is true.  The default is 1.

       DISP = boolean
              Set this equal to true if you are performing a finite displacements.   The  default
              is false.  Note: This is an old keyword which is now obsolete; it has been replaced
              by the JOBTYPE keyword.

       NDISP = integer
              This gives the maximum number of displacements if DISP is true.  The default is 1.

       NCASITER = integer
              This gives the maximum number of CASSCF iterations if WFN = CASSCF.  The default is
              1.

       CHECK = boolean
              If  this  is true, then psi3 will parse your input deck, and print out the sequence
              of commands to be executed.  The default is false.

       EXEC = string_vector
              The EXEC vector contains a list of commands  to  be  executed  by  psi3.   Explicit
              commands  can be entered in double quotes, or preset variables can be entered using
              the convention $variable (see examples below).  Thus if you want  to  run  ints  at
              some point, you could have

              psi: (
                exec = (
                  ...
                  "ints"
                  ...
                  )
                )

              or

              psi: (
                ints = "ints"
                exec = (
                  ...
                  $ints
                  ...
                  )
                )

              in your input.

LOOP CONTROL

       Loop control is handled via the "repeat" and "end" built-in commands.  The syntax is

        repeat n  [commands to be executed] end

       where n is the number of times to repeat the loop.  An inspection of the psi.dat file will
       show that this is how geometry optimizations and finite displacements are  performed;   in
       these cases n is set equal to NOPT or NDISP.

EXAMPLES

       Let's say you want to do an scf geometry optimization. Your psi3 input could then be:

       default: (
         jobtype = opt
         wfn = scf
         dertype = first
         reference = rhf
         nopt = 5
         ...
         )

       What  psi3  would  do  with  this  is  look in psi.dat or your input for a variable called
       SCFCLOSEDFIRSTOPT (you see,  psi  catenates  the  values  (roughly)  for  WFN,  REFERENCE,
       DERTYPE,  and  OPT/DISP,  in  approximately  that  order  (case doesn't matter)), and then
       executes the commands defined in the SCFCLOSEDFIRSTOPT vector.  Got it?

       So now, let's say you want to run a program "myscf" instead of whatever  scf  psi3  thinks
       you should run.  What you would do is put the line

        scf = "myscf"

       in your input.

       Okay,  one  last example, then you're on your own.  I want to run proper after deriv in my
       scf gradient. I would have several ways to do this.

       1) Brute force

              default: (
                exec = (
                 repeat 5
                   "cints"
                   "cscf"
                   $deriv       % this is defined in psi.dat as "cints --deriv1"
                   "oeprop"
                   $geomupdate  % this is defined in psi.dat
                 end
                 $done
                 )
                )

       2) Elegant

              default: (
                SCFFirst = ($ints $scf $deriv $oeprop)
                )

       3) Obscure

              default: (
                deriv = ("cints --deriv1" "oeprop")
                )

              And there are others.  The only limit is your own tortured imagination.

       Like I said, the best way to find out what psi3 can do is to look in psi.dat, and to  play
       around for awhile.  The CHECK option is very useful for this.  Good luck!

                                         25 August, 2003                                  psi3(1)