<s>
The	O
Reverse	B-Algorithm
Monte	I-Algorithm
Carlo	I-Algorithm
(	O
RMC	O
)	O
modelling	O
method	O
is	O
a	O
variation	O
of	O
the	O
standard	O
Metropolis	B-Algorithm
–	I-Algorithm
Hastings	I-Algorithm
algorithm	I-Algorithm
to	O
solve	O
an	O
inverse	O
problem	O
whereby	O
a	O
model	O
is	O
adjusted	O
until	O
its	O
parameters	O
have	O
the	O
greatest	O
consistency	O
with	O
experimental	B-General_Concept
data	I-General_Concept
.	O
</s>
<s>
This	O
method	O
is	O
often	O
used	O
in	O
condensed	O
matter	O
sciences	O
to	O
produce	O
atom-based	O
structural	O
models	O
that	O
are	O
consistent	O
with	O
experimental	B-General_Concept
data	I-General_Concept
and	O
subject	O
to	O
a	O
set	O
of	O
constraints	O
.	O
</s>
<s>
An	O
initial	O
configuration	O
is	O
constructed	O
by	O
placing	O
atoms	O
in	O
a	O
periodic	B-Algorithm
boundary	I-Algorithm
cell	O
,	O
and	O
one	O
or	O
more	O
measurable	O
quantities	O
are	O
calculated	O
based	O
on	O
the	O
current	O
configuration	O
.	O
</s>
<s>
Commonly	O
used	O
data	O
include	O
the	O
pair	O
distribution	O
function	O
and	O
its	O
Fourier	B-Algorithm
transform	I-Algorithm
,	O
the	O
latter	O
of	O
which	O
is	O
derived	O
directly	O
from	O
neutron	O
or	O
x-ray	O
scattering	O
data	O
(	O
see	O
small-angle	O
neutron	O
scattering	O
,	O
wide-angle	O
X-ray	O
scattering	O
,	O
small-angle	O
X-ray	O
scattering	O
,	O
and	O
X-ray	O
diffraction	O
)	O
.	O
</s>
<s>
The	O
move	O
is	O
accepted	O
with	O
the	O
probability	O
according	O
to	O
the	O
normal	O
Metropolis	B-Algorithm
–	I-Algorithm
Hastings	I-Algorithm
algorithm	I-Algorithm
,	O
ensuring	O
that	O
moves	O
that	O
give	O
better	O
agreement	O
with	O
experimental	B-General_Concept
data	I-General_Concept
are	O
accepted	O
,	O
and	O
moves	O
that	O
worsen	O
agreement	O
with	O
experimental	B-General_Concept
data	I-General_Concept
can	O
be	O
accepted	O
to	O
a	O
greater	O
or	O
lesser	O
extent	O
corresponding	O
to	O
how	O
much	O
the	O
agreement	O
has	O
worsened	O
.	O
</s>
<s>
The	O
resulting	O
atomic	O
configuration	O
should	O
be	O
a	O
structure	O
that	O
is	O
consistent	O
with	O
the	O
experimental	B-General_Concept
data	I-General_Concept
within	O
its	O
errors	O
.	O
</s>
<s>
The	O
most	O
notable	O
problem	O
is	O
that	O
often	O
more	O
than	O
one	O
qualitatively	O
different	O
model	O
will	O
give	O
similar	O
agreement	O
with	O
experimental	B-General_Concept
data	I-General_Concept
.	O
</s>
<s>
Since	O
the	O
RMC	O
method	O
follows	O
the	O
normal	O
rules	O
of	O
statistical	O
mechanics	O
,	O
its	O
final	O
solution	O
will	O
be	O
the	O
one	O
with	O
the	O
highest	O
degree	O
of	O
disorder	O
(	O
entropy	B-Algorithm
)	O
possible	O
.	O
</s>
<s>
Fundamental	O
Library	O
Language	O
for	O
Reverse	B-Algorithm
Monte	I-Algorithm
Carlo	I-Algorithm
or	O
fullrmc	O
is	O
a	O
multicore	O
RMC	O
modeling	O
package	O
.	O
</s>
<s>
fullrmc	O
is	O
a	O
fully	O
object-oriented	O
python	B-Language
interfaced	O
package	O
where	O
every	O
definition	O
can	O
be	O
overloaded	O
allowing	O
easy	O
development	O
,	O
implementation	O
and	O
maintenance	O
of	O
the	O
code	O
.	O
</s>
<s>
fullrmc	O
's	O
computation	O
blocks	O
and	O
modules	O
are	O
optimized	O
written	O
in	O
cython/C	O
.	O
</s>
<s>
fullrmc	O
supports	O
atomic	O
and	O
molecular	O
systems	O
,	O
all	O
types	O
(	O
not	O
limited	O
to	O
cubic	O
)	O
of	O
periodic	B-Algorithm
boundary	I-Algorithm
conditions	I-Algorithm
systems	O
as	O
well	O
as	O
the	O
so-called	O
infinite	O
boundary	O
conditions	O
to	O
model	O
nanoparticles	O
or	O
isolated	O
systems	O
.	O
</s>
<s>
Also	O
fullrmc	O
uses	O
Artificial	B-Application
intelligence	I-Application
and	O
Reinforcement	O
learning	O
algorithms	O
to	O
improve	O
the	O
ratio	O
of	O
accepted	O
moves	O
.	O
</s>
<s>
It	O
is	O
written	O
in	O
Fortran	B-Language
95	I-Language
with	O
some	O
Fortran	B-Application
2003	I-Application
features	O
.	O
</s>
<s>
RMC++	O
a	O
rewritten	O
,	O
C++	O
version	O
of	O
the	O
original	O
RMC	O
code	O
developed	O
by	O
McGreevy	O
and	O
Pusztain	O
.	O
</s>
<s>
Hybrid	O
Reverse	B-Algorithm
Monte	I-Algorithm
Carlo	I-Algorithm
(	O
HRMC	O
)	O
is	O
a	O
code	O
capable	O
of	O
fitting	O
both	O
the	O
pair	O
correlation	O
function	O
and	O
structure	O
factor	O
along	O
with	O
bond	O
angle	O
and	O
coordination	O
distributions	O
.	O
</s>
<s>
This	O
allows	O
the	O
code	O
to	O
fit	O
experimental	B-General_Concept
data	I-General_Concept
along	O
with	O
minimizing	O
the	O
total	O
system	O
energy	O
.	O
</s>
