.NH
.BM62
.CJ
#HAdditions/Corrections#N
.FJ

The following is a list of additions and corrections 
to the NBO 3.0 Program Manual
resulting from G90 enhancements and other modifications
of the NBO program.  Please
include a copy with the NBO program documentation.


.LM+3
.OS<<3//#_Section A.2 (page A-10):#/>>  


If you are compiling the NBO code on a 64-bit machine, note that
the NBO routines JOBOPT, DEBYTE, and NBOPEN #Imust#N be compiled with
64-bit integer arithmetic, not the standard 46-bit integer of some
compilers.

For the GAUSSIAN versions of the NBO program,
Read-Write Files 501, 528, 530, 536 and 538 are corrupted by the
NBO energetic analysis.  This may consequently affect the contents
of the checkpoint and archive files.  Beware of this if you plan
to restart jobs from the checkpoint file or use these files for
archival purposes.


.OS<<3//#_Section B.2.5 (page B-9):#/>>


The keyword FILE can be included in the $NBO keylist
to specify the filename of the external files employed by the NBO
program.  The FILE keyword is needed in order to avoid clashes
between concurrent jobs under some operating systems.

By default, the NBO program performs I/O with filenames of
the form FILE.nn,
where `nn' is a logical file number (LFN) discussed in Section B.2.4.  For 
example, ``FILE.48'' is the default filename of the NBO direct access file.
Specifying

     FILE=METHYLAMINE

will redirect I/O to files named ``METHYLAMINE.nn,'' so that, e.g.,
``METHYLAMINE.48'' is the NBO direct access file.  Note that file
extensions should not be included in the FILE specification.


.OS<<3//#_Section C.4 (page C-4):#/>>  


An additional `secondary' COMMON block has been
incorporated into the NBO program:

     COMMON/NBNAME/FILENM,NFILE,IFILE(MAXFIL)

This COMMON block stores information about the external filenames employed
by the NBO program (supporting the FILE keyword).  The PARAMETER statement

     PARAMETER (MAXFIL = 40)

determines the maximum number of sequential files that can be opened
by the NBO program (ignoring any restrictions of the operating
system):

.NP
.TB
.FM<<0C15//2C15//2L30>>
.RW-
.RW<<#Ivariable//type//meaning#N>>
.RW=
.FM<<0L15//2L15//2L30>>
.RW<>
.RW<>
.RW<>
.RW-
.ET


.OS<<3//#_Section C.4 (page C-12):#/>>  


The following change has been made to

     COMMON/NBONAV/IXDNBO(LENGTH),NBNAV,ISINGL

INTEGER variable ISINGL (the number of INTEGER words in a REAL*8
variable) has been moved from the PARAMETER statement into the
COMMON block, allowing the program to automatically reconfigure to
machines of different INTEGER length.


.OS<<3//#_Section C.5.1 (page C-17):#/>>  


NBOOPT(2) can have any INTEGER value
between 0 and 8.  Note that entries 2-8 have been erroneously shifted
upward by 1.


.OS<<3//#_Section C.7 (page C-27):#/>>  


The following routine has been added to the
NBO source code to reduce the operating-system dependence of file I/O

     SR NBFILE(NEW,ERROR)

This subroutine opens any sequential files to be employed 
by the NBO program, checking for possible conflicts.  The
filename (FILENM in COMMON/NBNAME/) is modified if file
conflicts occur.


.OS<<3//#_Section C.7 (page C-27):#/>>  


SR NBOPEN now automatically determines an appropriate physical
record length for the NBO direct access file, and sets ISINGL
of COMMON/NBONAV/
according to the INTEGER word length [ISINGL = 1(2) for 64(32) bit
machines].


.OS<<3//#_Section C.7 (page C-28):#/>>  


SR NBCLOS closes all external files, both
direct access and sequential, to facilitate OS independence.


.NP
.OS<<3//#_Section D.1 (page D-1):#/>>  


The NBO drivers for GAUSSIAN 90 are provided
with the distribution.  Unlike
the drivers for the other versions of the GAUSSIAN program, the NBO
program is directly integrated as L607 of GAUSSIAN 90.  See the
supplemental Appendix D.8, ``GAUSSIAN 90 VERSION,'' for information
pertaining to this version.


.OS<<3//#_Sections D.2.5, D.3.5, D.4.5:#/>>  


RWF 636 is used to store the NBO filename.


.OS<<3//#_Section D.8.2:#/>>


The fourth link in the suggested non-standard route for NBO energetic
analysis

     5/7=1,13=1/1,2;

must instead be replaced (as in the example at the bottom of the page) by 

     5/7=1,13=1/1;

for closed-shell calculations, or by

     5/7=1,13=1/2;

for open-shell calculations.  [Although the ``5/7=1,13=1/1,2;'' instruction
will give correct results in GAUSSIAN 82, 86, or 88 versions (for either
open- or closed-shell cases), the modified instruction 
should be used in these versions as well for maximum compatibility.]