<s>
The	O
COLUMBUS	B-Application
PROGRAMS	O
are	O
a	O
computational	O
chemistry	O
software	O
suite	O
for	O
calculating	O
ab	O
initio	O
molecular	O
electronic	O
structures	O
,	O
designed	O
as	O
a	O
collection	O
of	O
individual	O
programs	O
communicating	O
through	O
files	O
.	O
</s>
<s>
Some	O
features	O
employ	O
the	O
atomic	O
orbital	O
integrals	O
and	O
gradient	O
routines	O
from	O
the	O
Dalton	B-Application
as	O
well	O
as	O
MOLCAS	B-Application
program	O
suites	O
.	O
</s>
<s>
COLUMBUS	B-Application
is	O
distributed	O
open-source	O
under	O
the	O
LGPL	O
license	O
.	O
</s>
<s>
The	O
COLUMBUS	B-Application
PROGRAMS	O
are	O
frequently	O
used	O
for	O
nonadiabatic	O
problems	O
because	O
of	O
its	O
ability	O
to	O
calculate	O
MRCI	O
nonadiabatic	O
coupling	O
vector	O
analytically	O
.	O
</s>
<s>
The	O
COLUMBUS	B-Application
PROGRAMS	O
were	O
started	O
in	O
1980	O
in	O
the	O
Department	O
of	O
Chemistry	O
of	O
Ohio	O
State	O
University	O
by	O
Isaiah	O
Shavitt	O
,	O
Hans	O
Lischka	O
and	O
Ron	O
Shepard	O
.	O
</s>
<s>
The	O
programs	O
are	O
named	O
after	O
Columbus	B-Application
,	O
OH	O
.	O
</s>
<s>
The	O
COLUMBUS	B-Application
PROGRAMS	O
maintain	O
a	O
program	O
unique	O
style	O
that	O
distinguish	O
itself	O
from	O
most	O
other	O
quantum	B-Application
chemistry	I-Application
programs	I-Application
.	O
</s>
<s>
The	O
program	O
suite	O
is	O
a	O
collection	O
of	O
a	O
number	O
of	O
programs	O
coded	O
in	O
Fortran	B-Application
,	O
each	O
can	O
be	O
executed	O
independently	O
.	O
</s>
<s>
Perl	B-Language
scripts	O
are	O
provided	O
to	O
prepare	O
input	O
files	O
and	O
to	O
link	O
these	O
programs	O
together	O
to	O
perform	O
common	O
tasks	O
such	O
as	O
single	O
point	O
energy	O
calculation	O
,	O
geometry	O
optimization	O
,	O
normal	O
mode	O
analysis	O
,	O
etc	O
.	O
</s>
