The Mulliken Analysis Program

Revision: 1.3 Date: 1997/08/14 14:14:00


Table of Contents









 
 
                                  PREFACE
                                  _______
 
    This   manual   describes  the  ATMOL  Mulliken  Analysis  program,  as
implemented on the Cyber-205 at UMRCC. This document is one in a series  of
twelve, supporting the ATMOL packages on the Cyber-205.
 
 
                               ATMOL MANUALS
                               _____________
 
 
                          1.   Introduction.
                          2.   Allocator.
                          3.   Gaussian Integrals.
                          4.   Gaussian Library.
                          5.   SCF.
                          6.   APSG.
                          7.   Transformation.
                          8.   Direct CI.
                          9.   Mulliken Analysis.
                         10.   Graphical Analysis.
                         11.   Property.
                         12.   Service.
 
 
 
                             TABLE OF CONTENTS
                             _________________
 
 
    1.   Introduction.                                               1
    2.   The First Line of Data.                                     1
    3.   The TITLE Directive.                                        1
    4.   The OCCDEF Directive.                                       1
    5.   The MOPRINT Directive.                                      2
    6.   The ASSIGN Directive.                                       3
    7.   The VECTORS Directive.                                      3
    8.   The ENTER Directive.                                        4
    9.   Error Monitoring.                                           5
   10.   Specimen Jobs.                                              6
   11.   References.                                                 8
 
 
 

Introduction


 
    The ATMOL program for the Mulliken analysis of molecular  wavefunctions
is described. To invoke the Mulliken program on the Cyber-205 at UMRCC, use
the following JCL:
 
          PATTACH,ATMOL.
          MULL.
 
    In  default  the  Mulliken  program  will request 3 large pages of main
memory,  although  this  can  be  altered  by  the  use  of  one   of   the
pre-directives LPAGE or MEMORY [1].
 
    Data  input  and  printed  output  are  on  FORTRAN  streams  5  and  6
respectively. There is normally no need to mention thes streams in the JCL.
 
    The DUMP FILE containing the molecular orbitals (MOs)  to  be  analysed
may be assigned using any ATMOL file name (AFN).
 
    All  pre-directives  [1]  except  TIME  are  applicable  and  should be
presented before the program specific data described below.
 

The First Line of Data


 
    The first line of data is read to NBASIS,IBLKD,DDDUMP in format (2I,A).
 
    NBASIS specifies the number of basis functions as defined  at  integral
evaluation time. The maximum allowed value is 255.
 
    IBLKD  specifies the starting block of the DUMP FILE.
 
    DDDUMP specifies  the  AFN  of  the  DUMP  FILE.  This parameter may be
omitted, when the DUMP FILE will be assumed to be on ED3.
 
    The remainder of the data consists  of  directives.  Some  restrictions
have  been  imposed  on the order in which directives can be presented, the
recommended order being as follows (not all directives need be used).
 
The TITLE Directive
 
    Allows the user to define an  80  character  title  for  the  run,  and
extends  over  two  data lines. The first line contains the string TITLE in
the first data field, the second comprises the title.
 
    example:
 
      TITLE
      H2O --- MULLIKEN EXAMPLE
 
The OCCDEF Directive
 
    The  purpose  of  this  directive  is  to  allow the user to define the
'occupation numbers' for the molecular  orbitals  to  be  analysed.  It  is
envisaged that in most applications this directive will not be required. In
general the occupation numbers associated with a given set of  eigenvectors
will have been placed on the DUMP FILE by the SCF [2], APSG [3]  or  Direct
CI [4] programs in the Section used for MOs. Thus the OCCDEF directive need
only be used when the values on the DUMP FILE need be overridden.
 
    The first line contains the string OCCDEF  in  the  first  data  field.
Following  this  line  should  come  the 'occupation definition lines', the
first field of such a  line  being  read  in  F-format,  and  specifies  an
occupation  number  (OCC).  Subsequent fields are read in I-format. Let the
value of the integer specified in such an I-field be j. Then  the  j'th  MO
will be assigned the occupation number OCC. The following:
 
    2.0 1 2 3 4 7 8 9 10
 
assigns an occupation number of 2.0 to MOs 1 to 4 and 7 to 10. The line may
be shortened if sequences of consecutive integers appear by  means  of  the
string TO. Thus the abbreviated form of the above line is:
 
    2.0 1 TO 4 7 TO 10
 
The  occupation  definition  lines  are  presented  until all MOs have been
assigned occupation numbers, the  directive  being  terminated  by  a  line
containing  END in the first field. Any MO not mentioned explicitly will be
assigned an occupation number of zero.
 
    Each MO is analysed as if it contained  one  electron.  The  occupation
numbers  are only used in the evaluation of the Mulliken populations of the
total wavefunction.
 
    example:
 
        OCCDEF
        2.0 1 TO 5 7
        1.0 6
        END
 
The  first  five  MOs  and  MO  7  are doubly occupied while MO 6 is singly
occupied.
 
The MOPRINT Directive
 
    This directive specifies those MOs whose analysis is to be printed, and
consists  of  a single line containing the string MOPRINT in the first data
field. Subsequent data fields are read in I-format, the integers specifying
the  MOs.  An  abbreviated form of the MOPRINT directive allows the user to
introduce the string TO when specifying a sequence of consecutive integers.
Thus the following sequences:
 
    MOPRINT 2 3 4 7 8 9 11
 
and
 
    MOPRINT 2 TO 4 7 TO 9 11
 
are  equivalent.  The  MOPRINT directive may be omitted, in which case only
the Mulliken analysis of the total wavefunction will be printed.
 
The ASSIGN Directive
 
    The ASSIGN directive is used to assign basis functions to 'groups'. The
first  line  contains  the string ASSIGN in the first data field. Following
there should be 'basis function group assignment lines', at least one  line
per  group  being  required. The first data field of such a line is read in
A-format and should contain a user specified group label.  Subsequent  data
fields are read in I-format. Let the value of the integer specified in such
an I-field be j. Then the j'th basis function will be  assigned  the  group
label found in the first data field of the line. The following:
 
   G1 1 2 3 4 7 8 9 10
 
is a valid group assignment line. Such a line may be shortened if sequences
of consecutive integers appear,  by  means  of  the  string  TO.  Thus  the
abbreviated form of the above line is:
 
   G1 1 TO 4 7 TO 10
 
The  basis  function  group  assignment lines are presented until all basis
functions have been assigned a group label, when a data line containing the
string END in the first data field is presented to terminate the directive.
It is therefore not possible to use the text END  as  a  group  label.  Any
basis  function not assigned a group label by the user will be assigned the
label JUNK by the program.
 
    Note: The functions specified in the ASSIGN directive are  the  members
of  the  basis  set  employed  in the SCF [2] or APSG [3] calculation which
produced the MOs to be analysed. Thus if the  CTRANS  directive  was  used,
these functions are the LCBF's described in [2]. If no CTRANS directive was
presented, the functions are members of the 'original' basis set as defined
at integral evaluation time.
 
The VECTORS Directive
 
    This  directive  specifies  the Section of the DUMP FILE containing the
MOs to be analysed. The directive  consists  of  a  single  line,  read  to
variables TEXT,ISECT,ATEXT using format (A,I,A).
 
    TEXT    should be set to the string VECTORS.
 
    ISECT   the  eigenvectors to be analysed will be read from this Section
of the DUMP FILE.
 
    ATEXT   should be set to the string PRINT if a listing of  the  vectors
is required; if omitted the vectors will not be printed.
 
    example:
 
   VECTORS 1 PRINT
 
Eigenvectors are read from Section 1 of the DUMP FILE and printed.
 
 
The ENTER Directive
 
    This directive consists of a single line with the string ENTER  in  the
first  data  field.  The  directive  signals  that  no  more  data is to be
processed, and should be presented last. It is not possible to perform  the
analysis of more than one set of vectors in a single run of the program.
 
 

Error Monitoring


 
    A brief explanation of the possible error codes is given below:
 
  Error Code   Explanation
  __________   ___________
 
          16   Directive unknown.
          42   AFN not recognized.
          50   Invalid parameter in WIDTH pre-directive.
          61   Index block of DUMP FILE not in correct format.
          62   ATMOL block with invalid checksum has been read,
               or input/output error on ATMOL file. If the
               latter, a finite VSOS error code will be given
               whose explanation will be found in [5].
          63   A DUMP FILE Section number outside the allowed range of
               1 to 190 has been specified.
          64   An attempt has been made to retrieve an undefined section
               from the DUMP FILE.
          65   A DUMP FILE Section is of the wrong TYPE.
          67   Illegal search of an ATMOL file.
          68   Illegal character found in F-format data field.
          69   Illegal character found in I-format data field.
         200   Illegal value for NBASIS specified on the first data line.
         201   Invalid LCBF specified in the ASSIGN directive.
         202   Illegal number of LCBFs specified on a group
               assignment line of the ASSIGN directive.
         203   Number of groups specified by ASSIGN directive is invalid.
         204   ASSIGN directive omitted.
         205   Invalid MO specified in MOPRINT directive.
         206   Invalid MO specified in OCCDEF directive.
         207   Occupation numbers for the MOs to be analysed are not
               available. This condition will only arise when the vectors
               Section restored from the DUMP FILE does not contain
               occupation numbers, and the OCCDEF directive is omitted.
                                   ___
         208   VECTORS directive omitted.
         209   The vectors Section retrieved from the DUMP FILE is
               not in the correct format.
         210   Value of NBASIS specified on the first data line is not
               consistent with the vectors retrieved from the DUMP FILE.
         666   End of file condition detected on FORTRAN stream 5.
               The program expects more data.
         999   Insufficient main memory for the program to continue.
        3333   AFN not recognized in the FILE pre-directive.
 
 
 

Specimen Jobs


 
    Specimen Job 1
 
    This example is based on the H2O monomer with  integrals  generated  by
INTEGV.  The  vectors  are taken from Section 1 of the DUMP FILE, generated
from the closed shell scf example [2]. The group assignments break down the
basis  set  into  oxygen  S,  P  and  D  and hydrogen S and P orbitals. The
analysis of MOs 1 to 6 will be printed.
 
     /*JOB JOBNAME,ACCOUNT,ST=(C20,LP=1,WS=256),PW=PASSWORD,TI=9,C=A
     ATTACH,ED3V,ACC=RW.
     PATTACH,ATMOL.
     MULL.
     ####S
     LPAGE 1
     FILE ED3 ED3V
     25 1 ED3
     TITLE
     (H2O) MULLIKEN ANALYSIS (INTEGV INTS)
     MOPRINT 1 TO 6
     ASSIGN
     O(S) 1 TO 4
     O(P) 9 TO 14
     O(D) 21 TO 25
     H1(S) 5 6
     H2(S) 7 8
     H1(P) 15 16 17
     H2(P) 18 19 20
     END
     VECTORS 1
     ENTER
     ####S
 
 
    Specimen Job 2
 
    The  H2O  monomer  is  analysed again, but this time the integrals were
generated by INTEGW. The analysis of all 25 MOs will be printed. Note  that
the  ordering  of  the  basis  functions generated by INTEGV and INTEGW are
different.
 
     /*JOB JOBNAME,ACCOUNT,ST=(C20,LP=1,WS=256),PW=PASSWORD,TI=9,C=A
     ATTACH,ED3W,ACC=RW.
     PATTACH,ATMOL.
     MULL.
     ####S
     FILE ED3 ED3W
     LPAGE 1
     25 1 ED3
     TITLE
     (H2O) MULLIKEN ANALYSIS (INTEGW INTS)
     MOPRINT 1 TO 25
     ASSIGN
     O(S) 1 TO 4
     O(P) 5 TO 10
     O(D) 11 TO 15
     H1(S) 16 17
     H2(S) 18 19
     H1(P) 20 21 22
     H2(P) 23 24 25
     END
     VECTORS 1
     ENTER
     ####S
 
 
 

References


 
  [1] D.Moncrieff and V.R. Saunders, ATMOL-Introductory Notes.
  [2] D.Moncrieff and V.R. Saunders, ATMOL-SCF Program.
  [3] D.Moncrieff and V.R. Saunders, ATMOL-APSG program.
  [4] D.Moncrieff and V.R. Saunders, ATMOL-Direct CI program.
  [5] CDC VSOS Manual, Form 60459410, Control Data Corporation;
      VSOS Reference Manual, NAT 208, University of Manchester
      Regional Computer Centre, (1985).