<s>
The	O
Vienna	B-Application
Ab	I-Application
initio	I-Application
Simulation	I-Application
Package	I-Application
,	O
better	O
known	O
as	O
VASP	O
,	O
is	O
a	O
package	O
for	O
performing	O
ab	O
initio	O
quantum	O
mechanical	O
calculations	O
using	O
either	O
Vanderbilt	O
pseudopotentials	O
,	O
or	O
the	O
projector	O
augmented	O
wave	O
method	O
,	O
and	O
a	O
plane	O
wave	O
basis	O
set	O
.	O
</s>
<s>
Originally	O
,	O
VASP	O
was	O
based	O
on	O
code	O
written	O
by	O
Mike	O
Payne	O
(	O
then	O
at	O
MIT	O
)	O
,	O
which	O
was	O
also	O
the	O
basis	O
of	O
CASTEP	B-Application
.	O
</s>
