<s>
MOPAC	B-Application
is	O
a	O
popular	O
computer	B-Application
program	I-Application
used	O
in	O
computational	O
chemistry	O
.	O
</s>
<s>
It	O
is	O
designed	O
to	O
implement	O
semi-empirical	O
quantum	O
chemistry	O
algorithms	O
,	O
and	O
it	O
runs	O
on	O
Windows	B-Application
,	O
Mac	B-Application
,	O
and	O
Linux	B-Application
.	O
</s>
<s>
MOPAC	B-Application
was	O
largely	O
written	O
by	O
Michael	O
Dewar	O
's	O
research	O
group	O
at	O
the	O
University	O
of	O
Texas	O
at	O
Austin	O
.	O
</s>
<s>
Its	O
name	O
is	O
derived	O
from	O
Molecular	O
Orbital	O
PACkage	O
,	O
and	O
it	O
is	O
also	O
a	O
pun	O
on	O
the	O
Mopac	B-Application
Expressway	O
that	O
runs	O
around	O
Austin	O
.	O
</s>
<s>
The	O
latest	O
versions	O
are	O
no	O
longer	O
public	B-Application
domain	I-Application
software	I-Application
as	O
were	O
the	O
earlier	O
versions	O
such	O
as	O
MOPAC6	O
and	O
MOPAC7	O
.	O
</s>
<s>
An	O
open	O
source	O
version	O
of	O
MOPAC7	O
for	O
Linux	B-Application
is	O
also	O
available	O
.	O
</s>
<s>
The	O
author	O
of	O
MOPAC	B-Application
,	O
James	O
Stewart	O
,	O
released	O
in	O
2006	O
a	O
public	O
domain	O
version	O
of	O
MOPAC7	O
entirely	O
written	O
in	O
Fortran	B-Application
90	O
called	O
MOPAC7.1	O
.	O
</s>
