i n n ppppp u u ddddd
i nn n p p u u d d
i n n n p p u u d d
i n n n ppppp u u d d
i n nn p u u d d
i n n p uuuu ddddd
introductory guide to the input program "inpud" with implementation aids.
contents
0. general remarks
1. input files
1.1 basis set data
1.2 atomic orbitals for eht
1.3 pseudopotentials
1.4 molecular geometry
1.5 extensions
2. output files
2.1 the integral input file "intinp"
2.2 the scf input file "scfinp"
2.3 the coordinate file "coord" (optional)
2.4 the pseudopotential file "pseudo" (optional)
2.5 the sao info file "sao.info"
2.6 the extended hueckel output files
2.6.1 the "inteht"-file
2.6.2 the "moeht"-file
2.6.3 the "scfeht"-file
2.7 the properties program input file "proinp" (optional)
2.8 the relax program input file "rexinp" (optional)
3. temporary files
4. extended hueckel option
0. general remarks
this is the guide to the interactive turbomole input generator.
the input program provides input files for the electronic structure
programs dscf,gradient, relax, and property (and the subsidiary programs
moder and expand), and also for the integral transformation program
kora and the analytical second derivatives program force.
molecular symmetry is efficiently used by all these programs. symmetry
information can be derived from the schoenfliess symbol of the molecular
point group, e.g. c1, c2v, d5d, td, or ih. for all finite point groups
the input program has default generators (e.g. c2(z) and sigma(xz) for
the c2v group) which will be displayed on standard output.
basis sets, atomic orbitals (for an optional extended hueckel guess), and
pseudo-potentials (optional) are taken from a library of files which is
described in section 1.
atomic coordinates may be specified interactively (symmetry dependent
nuclei are calculated from the mol. point group), or may be provided
by means of a file containing coordinates and element symbols ("coord").
atomic coordinates have to be expressed in atomic units, not in angstroems
or in picometers !
occupation numbers (for molecules with symmetry) can be input or may be
generated by means of an extended hueckel guess.
the extended hueckel guess may also be used for the generation of start
vectors which is recommended if no other source for a start vector is
available.
the extended hueckel guess may not always lead to the correct electronic
ground state. in complicated cases check carefully! for open shell calcu-
lations and calculations of excited states occupation numbers can be chosen
with significant support from the eht guess (described in section 4).
for performing the extended hueckel guess one must supply atomic orbitals
and their eigenvalues in a suitable basis set (default: double zeta dz);
in the basis set library such files can be found for many elements xy
- such files are termed xy#eht or xy#ehtn where n is the number of core
electrons absorbed in an ecp (section 4).
for geometry optimizations an input file for the relax program "rexinp"
will be needed. usually the optimization is done by means of internal
coordinates which have to be specified in file "rexinp". while "rexinp" is
basically provided by the inpud program this is not true for the internal
coordinates which have to be chosen and specified by the user. thus
y o u have to edit "rexinp" after the inpud program has output "rexinp"
with all flags properly set.
1. input files
1.1 basis set data
in the interactive input session you may choose atoms and basis sets
when the program asks for
ATOM SYMBOL AND BASIS SET NAME (END=*,
REPEAT=&,HELP=help,DISTANCE LIST=dist) .
if you want to choose a dz basis for a group of carbon atoms you
type in (left bound)
c dz
the program (subroutine getbas) then retrieves basis set data from
file "c" in the basis set library "basen" - this basis set information
will later be incorporated into the file "intinp" (reference: dscf
documentation).
you may search file "c" for basis sets in an interactive mode if
you use the question mark to abbreviate basis nicknames, e.g.
c sto?
will give you the opportunity to choose among all sto-ng basis sets
for carbon.
if basis set data for atom xy cannot be found "inpud" issues messages
like
1.
FILE /path/xy HAS NOT BEEN FOUND IN THE BASIS SET LIBRARY
or (MVS)
FILE dataset(xy) HAS NOT BEEN FOUND IN THE BASIS SET LIBRARY
2.
BASIS SET xy nick HAS NOT BEEN FOUND IN
BASIS SET LIBRARY FILE /path/xy
in case 1 check
1. is the basis set library installed - what's its full name
in your installation ? is file xy in place ?
2. the complete filename should coincide with the name issued
by inpud. if not rename your basis set library or enter its
location in the INSTALLATION SECTION of "inpud". see turbo-
mole's documentation paragraph 5 and also see below.
in case 2 check
does the basis set you want exist in the basis set library ?
the concept of storing all basis sets of some element xy in a file
xy is explained below :
1. any line starting with '#' is a comment line which is displayed
by the inpud-program
comments may be inserted in the basis header (see below) or at the
very beginning of the file
2. asterisks '*' are delimiter which separate basis sets and their
headers
3. the last line contains a slash '/'
4. each basis set starts with a header which contains comments and
basis set nicknames like "c dz" which is a double zeta quality basis
set for carbon. each basis set may have multiple nicknames.
if a basis set is to be used with an effective core potential (ecp)
at least one of the nicknames has to contain the string ecp-n where
n is a one- or two-digit number indicating how many electrons are
absorbed into the ecp.
5. after the header and separated by a line with an asterisk '*' the
basis set is defined (exponents left, contraction coefficients
right, each contraction is headed by two integers : contraction
level and l+1).
below you see the beginning of the basis set file for carbon :
#
# basis set library for carbon
# last update : 03/30/89
#
# abbreviation hondo refers to version 7.0 of hondo
#
*
c 8s4p
c dz
# huzinaga 8s4p e(3p) = -37.679844
# default contraction -37.673959
*
5 1
2779.4685 .20556017e-02
417.66068 .15639441e-01
95.487919 .75238134e-01
27.079569 .24500093
8.7492390 .46689924
1 1
3.0435897 .33536648
1 1
.52758185 -.53502954
1 1
.16137209 -.58945468
3 2
9.6894727 .36773971e-01
2.0536919 .20411162
.55875504 .50524418
1 2
.15448426 .47798652
*
c 8s4p1d
c dzp
# huzinaga 8s4p e(3p) = -37.679844
# default contraction -37.673959
# 8s/4s (5111) 4p/2p (31) +1d (0.8)
*
5 1
2779.4685 .20556017e-02
417.66068 .15639441e-01
95.487919 .75238134e-01
27.079569 .24500093
8.7492390 .46689924
1 1
3.0435897 .33536648
1 1
.52758185 -.53502954
1 1
.16137209 -.58945468
3 2
9.6894727 .36773971e-01
2.0536919 .20411162
.55875504 .50524418
1 2
.15448426 .47798652
1 3
.80000000 .00000000e+00
*
c 8s4p2d
c dz2p
# huzinaga 8s4p e(3p) = -37.679844
# default contraction -37.673959
# 8s/4s (5111) 4p/2p (31) +2d (0.46,1.39)
*
5 1
2779.4685 .20556017e-02
417.66068 .15639441e-01
95.487919 .75238134e-01
27.079569 .24500093
8.7492390 .46689924
1 1
3.0435897 .33536648
1 1
.52758185 -.53502954
1 1
.16137209 -.58945468
3 2
9.6894727 .36773971e-01
2.0536919 .20411162
.55875504 .50524418
1 2
.15448426 .47798652
1 3
.46000000 .00000000e+00
1 3
1.3900000 .00000000e+00
*
c 9s5p
c tz
# huzinaga 9s5p e(3p) = -37.685269
# default contraction -37.684671
# 9s/5s (51111) 5p/3p (311)
*
5 1
4240.3098 .12152226e-02
637.77827 .92731586e-02
146.74534 .45279235e-01
42.531428 .15492334
14.184804 .35808349
1 1
5.1756943 .43427160
1 1
2.0072531 .14932812
1 1
.49677422 -.57313491
1 1
.15348718 -.54851147
3 2
18.099144 .14760512e-01
3.9769145 .91649350e-01
1.1450768 .30392714
1 2
.36188831 .50711806
1 2
.11460548 .31988309
*
/
for basis sets which are used in connection with an effective
core potential, the following convention for the basis set name
is recommended :
ecp--
where is a string of 3 characters specifying
an abbreviation of ecp data also used in the ecp data files
(see chapter 1.3. for further comments).
it is easy to change basis sets or to add new ones to the lib.
generalized contractions may be used but should be avoided.
1.2 atomic orbitals for eht
these are only needed for the extended hueckel guess (automatic
generation of occupation numbers and start vectors).
the atomic orbitals for each element xy can be found in the basis
set library under the name xy#eht (eht stands for extended hueckel
theory). if atom xy is to be used with an effective core potential
for 10 electrons the filename for the atomic orbitals is xy#eht10.
the input program inpud looks for these files when needed for the
extended hueckel guess.
if you look at such a file xy#eht you will recognize the following
structure :
the first line has to start with the string "EHT DATA"
- otherwise the first two lines are comment lines;
the third line contains an asterisk '*' as separator;
the atomic basis set follows next;
again an asterisk as separator;
then the atomic orbitals are specified in the same way as
output by the dscf program (to unit 12 = file mo12) if an
atomic scf calculation were performed using symmetry group
c1.
if you want to prepare an atomic orbital file for an element xy
with pseudo potential for n electrons you have to perform
a dscf calculation for atom xy in a basis set of your choice
(watch out for the correct electronic state which for transition
metals is not uniquely defined !!! choose the basis set in accord
with the electronic state !) and an effective core potential for
n electrons. choose symmetry group c1 !
then prepare the first two comment lines, copy the basis set used
in the atomic dscf-calculation behind the third line (asterisk),
append a line with asterisk, and append the dscf output file "mo12"
(atomic orbitals).
sometimes in the dscf calculation the cartesian components within some
atomic shell mix. this has to be avoided. if you have problems you
may do the calculation in say d9h and convert the "mo12" to c1-symmetry
with program "moder".
below the atomic orbitals of selenium (se#eht28) are listed as an
example :
eht data for selenium
christiansen 3s3p basis set (for an averaged relativistic effective potential)
*
1 1
1.3400000 -.388566
1 1
0.3717000 .788462
1 1
0.1322000 .476038
1 2
2.1420000 -.058692
1 2
0.3854000 .580848
1 2
0.1195000 .533513
*
se(3p) [ar]s2p4 dz for an arep with 28 core electrons
se(3p) [ar]s2p4 dz for an arep with 28 core electrons
1 1
(4e20.14)
a
12 4 1 3
2.000000000 .000000000 .000000000 .000000000
.000000000 1.333333333 1.333333333 1.333333333
-.88855437739660e+00 .95347174107152e+00 .80312411517214e+00 .00000000000000e+00
.00000000000000e+00 .00000000000000e+00 .00000000000000e+00 .00000000000000e+00
.00000000000000e+00 .00000000000000e+00 .00000000000000e+00 .00000000000000e+00
.00000000000000e+00 .00000000000000e+00 .00000000000000e+00-.70517331764456e-01
.00000000000000e+00 .00000000000000e+00 .63351024483907e+00 .00000000000000e+00
.00000000000000e+00 .48132184771613e+00 .00000000000000e+00 .00000000000000e+00
.00000000000000e+00 .00000000000000e+00 .00000000000000e+00 .00000000000000e+00
-.70517331764456e-01 .00000000000000e+00 .00000000000000e+00 .63351024483907e+00
.00000000000000e+00 .00000000000000e+00 .48132184771613e+00 .00000000000000e+00
.00000000000000e+00 .00000000000000e+00 .00000000000000e+00 .00000000000000e+00
.00000000000000e+00-.70517331764456e-01 .00000000000000e+00 .00000000000000e+00
.63351024483907e+00 .00000000000000e+00 .00000000000000e+00 .48132184771613e+00
-.79734289493574e+00-.56545964640609e+00-.56545964640609e+00-.56545964640609e+00
.000000000 -1.000000000
0 0
1 2 3 4
if you want to specify your own basis set and corresponding atomic
orbitals (for the extended hueckel !) you may do that by telling
the "inpud" program the names of the files where you provide these data
(they will be asked for if you choose the non-default option).
if you want to know how the atomic orbitals are incorporated into the
extended hueckel guess refer to section 4.
1.3 pseudopotentials
if you want to make a calculation with effective core potentials,
you can either use one of the basis set commands (i.e., the command
pseudo) or by using a basis set the name of which contains the
string 'ecp-n' where n is a one- or two-digit integer corresponding
to the number of electrons absorbed into the ecp. then a subroutine
"psepin" will be called which is to generate the ecp-input file "pseudo".
in the present version it is assumed that only ecp's following the
definition by kahn, i.e.
u = u(lmax) + sum(l=0,...,lmax-1,m=l,..,-l) ( u(l) - u(lmax) ) *
* | lm > < lm |
are used. u(lmax) is optional.
it is assumed that the ecp-input data for element xy are allocated
in the basis set library under the name xy#ecp (fortran unit is 27).
subroutine psepin asks you to choose among the possibilities remaining
under the constraints set by the choice of the basis set.
one block of ecp-data in a library file has following appearance :
first line : -ecp(-), number of
core electrons, lmax (see above)
format : a10,i3,i5
is a string of 3 characters serving for a more
detailed specification of ecp data (if there are several
ecp data sets at hand, for example). this string, together
with the leading hyphen, may be omitted.
the following data refer on u(lmax),u(0)-u(lmax),...,
u(lmax-1)-u(lmax) (in this order).
each term is represented as a sum of m gaussians, weighted by
r**(-n). m may be zero.
the length m of the sum is specified in i5-format, followed
by m lines containing
coefficient of gaussian - exponent n - exponent of gaussian
format : f14.8,i5,f14.8
the following is an ecp for cu with 10 core electrons and
lmax=2
cu-ecp 10 2
# comment-line (must follow the first line)
3 u(d)
-10.00000000 1 511.9951763
-72.55482820 2 93.2801074
-12.74502310 2 23.2206669
4 u(s)-u(d)
3.00000000 0 173.1180854
23.83518250 1 185.2419886
473.89304880 2 73.1517847
157.63458230 2 14.6884157
4 u(p)-u(d)
5.00000000 0 100.7191369
6.49909360 1 130.8345665
351.46053950 2 53.8683720
85.50160360 2 14.0989469
1.4 molecular geometry
this file (fortran unit 50) may be used optionally (when the inpud
program asks
IF YOU WANT TO READ ELEMENT SYMBOLS AND COORDINATES FROM FILE
INPUT THE FILE NAME - OTHERWISE HIT >RETURN< TO CONTINUE OR
INPUT help FOR HELP
enter the name of the file prepared by you. using the help-option
gives you the file specifications to be met.
this choice will speed up your input session if a list of atomic coor-
dinates is available from previous or (semi-)empirical calculations.
all atoms must be listed with their cartesian coordinates in accord
with the molecular point group chosen before (symmetry will be checked
to 10 digits).
an example for methane is listed below :
0. 0. 0. c
1.1 1.1 1.1 h
-1.1 -1.1 1.1 h
-1.1 1.1 -1.1 h
1.1 -1.1 -1.1 h
1.5 extensions
in our UNIX version it is possible to read the files of a
previous (series of) dscf-calculation(s) -
/path/intinp , /path/scfinp , /path/mo12
- and to use them to generate the input files for a new
calculation (employing a different basis set !); this includes
determination of occupation numbers and a corresponding
start vector (if you let "inpud" invoke the basis set
expansion program "blowup"). this procedure is similar
to the extended hueckel guess procedure.
2. output files
2.1 the integral input file "intinp"
this file has the fortran unit 24 and is output by subroutine diout.
it contains basis set data and atomic coordinates of the molecule
chosen for calculation. also some flags, thresholds, and the schoen-
fliess symbol are specified in this file.
for examples and a detailed description refer to the dscf documentation.
the "intinp" file will be used by the dscf, moder, expand, gradient,
property, kora, and force programs.
2.2 the scf input file "scfinp"
this file has the fortran unit 32 and is output by subroutine dsout.
it contains occupation numbers and flags, thresholds, damping con-
stants and possible shifts for the scf procedure.
for examples and a detailed description refer to the dscf documentation.
the "scfinp" file will be used by the dscf program, and by the moder
program.
2.3 the coordinate file "coord" (optional)
this file has the fortran unit 28 and contains atomic coordinates.
see the description in the dscf documentation.
2.4 the pseudopotential file "pseudo" (optional)
this file has the fortran unit 26 and is output by subroutine psepin.
it contains all pseudopotentials chosen for the molecule. please
refer to the dscf documentation for further details. "pseudo" will
be used by dscf and gradient "egrad".
2.5 the sao info file "sao.info"
this file has the fortran unit 99 and is output by the main
program if desired.
it documents the choice of the sao's (symmetrized atomic basis
functions). it is not an input file to any of the programs but
only serves documentation purposes.
the mo-vectors generated by the dscf-program and output on standard
output are in terms of these sao's.
an example of an sao.info file (nh3 in dzp) is shown below :
sao-info file : construction of saos from aos
ao-references are by atom index, element symbol, and ao-type
representation a1 contains 1* 11 basis functions :
1 th column of a1
sao index within symmetry species : 1 cumulative sao index : 1
1.000* 1n s
sao index within symmetry species : 2 cumulative sao index : 2
1.000* 1n s
sao index within symmetry species : 3 cumulative sao index : 3
1.000* 1n s
sao index within symmetry species : 4 cumulative sao index : 4
1.000* 1n s
sao index within symmetry species : 5 cumulative sao index : 5
1.000* 1n pz
sao index within symmetry species : 6 cumulative sao index : 6
1.000* 1n pz
sao index within symmetry species : 7 cumulative sao index : 7
0.289* 1n dz2
sao index within symmetry species : 8 cumulative sao index : 8
0.577* 2h s 0.577* 3h s 0.577* 4h s
sao index within symmetry species : 9 cumulative sao index : 9
0.577* 2h s 0.577* 3h s 0.577* 4h s
sao index within symmetry species : 10 cumulative sao index : 10
0.577* 2h px -0.289* 3h px 0.500* 3h py -0.289* 4h px
-0.500* 4h py
sao index within symmetry species : 11 cumulative sao index : 11
0.577* 2h pz 0.577* 3h pz 0.577* 4h pz
representation a2 contains 1* 1 basis functions :
1 th column of a2
sao index within symmetry species : 1 cumulative sao index : 12
0.577* 2h py -0.500* 3h px -0.289* 3h py 0.500* 4h px
-0.289* 4h py
representation e contains 2* 9 basis functions :
1 th column of e
sao index within symmetry species : 1 cumulative sao index : 13
1.000* 1n px
sao index within symmetry species : 2 cumulative sao index : 14
1.000* 1n px
sao index within symmetry species : 3 cumulative sao index : 15
1.000* 1n dxz
sao index within symmetry species : 4 cumulative sao index : 16
-0.500* 1n dx2
sao index within symmetry species : 5 cumulative sao index : 17
0.816* 2h s -0.408* 3h s -0.408* 4h s
sao index within symmetry species : 6 cumulative sao index : 18
0.816* 2h s -0.408* 3h s -0.408* 4h s
sao index within symmetry species : 7 cumulative sao index : 19
0.816* 2h px 0.204* 3h px -0.354* 3h py 0.204* 4h px
0.354* 4h py
sao index within symmetry species : 8 cumulative sao index : 20
0.612* 3h px 0.354* 3h py 0.612* 4h px -0.354* 4h py
sao index within symmetry species : 9 cumulative sao index : 21
0.816* 2h pz -0.408* 3h pz -0.408* 4h pz
2 th column of e
sao index within symmetry species : 1 cumulative sao index : 22
1.000* 1n py
sao index within symmetry species : 2 cumulative sao index : 23
1.000* 1n py
sao index within symmetry species : 3 cumulative sao index : 24
1.000* 1n dyz
sao index within symmetry species : 4 cumulative sao index : 25
1.000* 1n dxy
sao index within symmetry species : 5 cumulative sao index : 26
0.707* 3h s -0.707* 4h s
sao index within symmetry species : 6 cumulative sao index : 27
0.707* 3h s -0.707* 4h s
sao index within symmetry species : 7 cumulative sao index : 28
-0.354* 3h px 0.612* 3h py 0.354* 4h px 0.612* 4h py
sao index within symmetry species : 8 cumulative sao index : 29
0.816* 2h py 0.354* 3h px 0.204* 3h py -0.354* 4h px
0.204* 4h py
sao index within symmetry species : 9 cumulative sao index : 30
0.707* 3h pz -0.707* 4h pz
the sao's are ordered according to their symmetry properties.
let us consider the sao number 7 in the representation e row/column 2
which transforms according to the second row of the e-representation.
from the sao.info file you find that this sao is a linear combination
of p-orbitals (polarization functions) at hydrogen atoms (element sym-
bol h as specified). more explicitly the sao is defined as
-.354*(px basis function at atom number 3 (=h))
+.612*(py basis function at atom number 3 (=h))
+.353*(px basis function at atom number 4 (=h))
+.612*(py basis function at atom number 4 (=h)) .
note that the linear coefficients are accurate to 12 digits, but only
the first 3 digits are output.
in the example .354 corresponds to 1/sqrt(8) while .612 corresponds to
sqrt(3/8).
all sao's are normalized to one if the overlap between basis functions
is neglected.
2.6 the extended hueckel output files
2.6.1 the "inteht"-file
the inteht file documents atomic coordinates and the basis set used
in the extended hueckel guess (subroutine eht). its fortran unit num-
ber is 25.
the formats in the inteht file are the same as in all intinp files
(see 1.1).
despite the default basis for the eht being a double zeta (dz),
this is no longer true for the basis set output to the inteht file.
the mo vectors produced by the eht guess are expressed in atomic
orbitals as calculated by the dscf and input to the inpud program
via unit 13 (section 1.2). therefore the basis set is changed to
single zeta generalized contraction (according to the ao's).
for more details see section 4.
the inteht file is normally used as an input file to the expand
program.
2.6.2 the "moeht"-file
the moeht file contains the mo vectors put forward by the eht guess.
its fortran unit number is 12.
the mos are expressed in the basis which is documented in the inteht
file.
the mos are normally used as start mos for the dscf. since it is not
advised to use the basis set on the inteht file for a dscf (gene-
ralized contraction is not efficiently implemented) one has to trans-
form the vectors on the moeht file to the desired basis set. this can
cheaply be done with the expand program, which needs the moeht file
(vectors to be projected), the inteht file, and the integral input
file for the new basis set in which the vectors are to be expressed.
in a UNIX environment "inpud" may invoke the expand program "blowup".
2.6.3 the "scfeht"-file
this is the scf input file which corresponds to the inteht and moeht
files. its fortran unit number is 33.
usually the scfeht file will not be used unless one intends a dscf
calculation in the generalized single zeta basis specified in inteht.
it should be noted that this is not recommended.
2.7 the properties program input file "proinp" (optional)
the inpud program optionally generates an input file "proinp"
(fortran unit 63 in subroutine prphlp) for the properties program
(calculation of first order properties, population analyses, and
localized orbitals).
generally, file "proinp" is designed as follows :
the first line is a comment-line.
the second line contains six integer-numbers, given in format 6i5,
of which the last three deserve comments, the other ones being set
to zero (which is the default for all these numbers).
the fourth number if set to a value different from zero makes the
properties program output individual mo-contributions to properties.
this means, if
x = sum(i) nocc(i) * < i | xop | i >
is the eigenvalue of the operator xop all matrix elements
will be printed.
the fifth number, if set to one, prevents output of modified atomic
orbitals (as utilized in the roby/davidson-population analysis) to
a file "mao".
the sixth number, if set to one, prevents printing of maos to the
standard output. since either a population analysis or a boys
localization is allowed in a properties-run, this variable serves
also for printing out the mo rotation matrix obtained in the
localization procedure onto a file named "rotor".
the line(s) which follow the second one specify the kind(s) of
propert(y)/(ies) to be calculated.
the general input line consists of an integer flag, a short comment,
another integer flag and three coordinates in the format (i5,6x,a4,
i5,3f10.5)
the first integer denotes the kind of property, the coordinates denote
the point of reference (e.g., the point, at which an electrostatic
potential is to be calculated). if this point coincides with a
nucleus, the number of this nucleus can be specified as the
second integer.
now a list of possible options (= kinds of properties) :
1 --- electrostatic potential
2 --- electric field
3 --- field gradient
4 --- dipole moment
5 --- quadrupole moment
6 --- third moment
7 --- planar density
8 --- linear density
9 --- charge density
10 --- overlap ( xop = unity operator )
11 --- second moment
12 --- diamagnetic shielding
13 --- relativistic correction ( xop = cowan griffin
operator )
14 --- mulliken- and roby/davidson-population analysis
15 --- boys localization
watch out : options 14 and 15 exclude each other which is due to the
program structure.
these two options, 14 and 15, need further input.
a) population analysis
(mulliken and roby-davidson (see c.ehrhardt, r.ahlrichs, theor.
chim.acta 68:231-245(1985), and references therein))
for every atom the total number of mao's (modified atomic orbitals)
to be selected must be given. in special cases it may be necessary
to choose mao's explicitely (by specifying their indices -then
one already must have carried out a population analysis).
this information is given in the format (5x,i5,20i3) for each atom.
b) boys localization
in "proinp" the total number of molecular orbitals to be localized
is provided in the format (5x,i5). if this number is different from
zero the indices of these mo's have to be supplied thereafter in the
format (5x,5i5) (ordering of mo's according to ordering in the mo-
input file of the properties program).
if, however, the total number of mo's to be localized is set to zero
the properties program understands that all mo's with an orbital energy
above some threshold shall be localized. this threshold is supplied
in the next input line. default is -2.0 hartree.
finally, the total number of operators for localization is specified
in format (5x,i5). a zero would be interpreted as : all operators -
the possible choices include x ( <=> 1 ), y ( <=> 2 ) and z ( <=> 3 )
- thus a zero induces a localization in three dimensions. for linear
or planar molecules, one should input 1 or 2, respectively, and provide
the indices of operators in the following line to obtain sigma-pi-
separation.
example : if a planar molecule is in the xz-plane one may set
2 ---> total number of operators
1 3 ---> indices of operators (1 for x,3 for z)
this description explained the appearence of the "proinp" file.
clearly, using this inpud program, you need not bother about the
formats explained above.
2.8 the relax program input file "rexinp" (optional)
the "rexinp" file (fortran unit 64) is optionally provided
by the inpud program. "rexinp" will be needed for an update
of cartesian coordinates from cartesian gradients (as output
by the gradient program) and from a approximate force constant
matrix or with the aid of the diis procedure. this is usually
done by means of internal coordinates with the program relax,
but it is also possible to carry out an up-date in cartesian
coordinates.
conversion cartesian <--> internal coordinates is also
a task of "relax" as well as relaxation of basis set exponents.
all these tasks are directed by "rexinp".
the inpud program currently supports only the generation of
a skeleton "rexinp" file which contains only the option flags
for the relax program.
the "rexinp" file, however, is to contain the specifications
of all internal coordinates according to the rules given in
the header of the relax program.
it may also contain a start for the approximate force con-
stant matrix.
this information is to be added by the user. it cannot be
supplied by the inpud program (yet).
3. temporary files
only one temporary (scratch) file is used during program execu-
tion : unit 10. character strings (a80) will be written to unit
10.
4. extended hueckel option
the inpud program can be used as an extended hueckel program.
extended hueckel energies are available on standard output,
extended hueckel mo's can be output to unit 12 ("moeht"), while
corresponding basis set information is output to unit 25
("inteht"). occupation number information may be output to unit 33
("scfeht").
in general the extended hueckel option is useful for generating
occupation numbers and start vectors. the start vectors ("moeht")
can be transformed to any desired basis set by means of the basis
set expansion program expand. they may then be utilized for subsequent
dscf calculations.
in the default case the extended hueckel calculation is performed
on the basis of atomic orbitals of the atoms in their electronic ground
states (as calculated by the dscf in a (huzinaga) double zeta basis).
the atomic orbitals (and their orbital energies) are then used to
calculate the hueckel matrix (orbital energy weighted overlap matrix,
weighted also with interatomic bond constants (default is 1.7)).
diagonalization of the hueckel matrix provides the hueckel mos
and their corresponding eigenvalues. occupation numbers are assigned
according to the energetic order of the extended hueckel mos.
for near-degenerate homo/lumo-pairs and open shell molecules or
excited states the assignment of occupation numbers has to be
carried out interactively aided by the extended hueckel results as
a data base.
for the interactive determination of occupation numbers a variety
of commands may be invoked which either provide information or act
upon the electronic structure, e.g. the command 'all' gives an over-
view about all molecular orbitals (symmetry properties, orbital
energy, occupation), while the command 'c 1 7' makes the orbital
shells number 1 to 7 to be closed shell orbitals.
all commands will be listed if the command 'help' is entered.
it is also possible to use other atomic orbitals than the defaults.
all you have to do is to take a basis set, do the atomic calculation
for the desired atomic/ionic state with the dscf in c1-symmetry,
and supply both to the inpud program (choose non-default option,
the inpud program will ask for the names of the corresponding files).
follow the outline given in paragraph 1.2 .
a warning is appropriate at this point : do not trust too much on
extended hueckel theory (=eht) !