Page Menu
Home
c4science
Search
Configure Global Search
Log In
Files
F83536355
CbPotential.cpp
No One
Temporary
Actions
Download File
Edit File
Delete File
View Transforms
Subscribe
Mute Notifications
Award Token
Subscribers
None
File Metadata
Details
File Info
Storage
Attached
Created
Tue, Sep 17, 16:32
Size
2 KB
Mime Type
text/x-c
Expires
Thu, Sep 19, 16:32 (2 d)
Engine
blob
Format
Raw Data
Handle
20793557
Attached To
rLAMMPS lammps
CbPotential.cpp
View Options
#include "CbPotential.h"
#include <cmath>
namespace
ATC
{
static
const
double
EPS
=
1.0e-8
;
// Approximates the derivative of phi
double
CbPotential
::
phi_r
(
const
double
&
r
)
const
{
const
double
dr
=
r
*
EPS
;
return
(
phi
(
r
+
dr
)
-
phi
(
r
))
/
dr
;
}
// Approximates the second derivative of phi
double
CbPotential
::
phi_rr
(
const
double
&
r
)
const
{
const
double
dr
=
r
*
EPS
;
return
(
phi_r
(
r
+
dr
)
-
phi_r
(
r
))
/
dr
;
}
// Approximates the third derivative of phi
double
CbPotential
::
phi_rrr
(
const
double
&
r
)
const
{
const
double
dr
=
r
*
EPS
;
return
(
phi_rr
(
r
+
dr
)
-
phi_rr
(
r
))
/
dr
;
}
// Approximates the derivative of rho
double
CbPotential
::
rho_r
(
const
double
&
r
)
const
{
const
double
dr
=
r
*
EPS
;
return
(
rho
(
r
+
dr
)
-
rho
(
r
))
/
dr
;
}
// Approximates the second derivative of rho
double
CbPotential
::
rho_rr
(
const
double
&
r
)
const
{
const
double
dr
=
r
*
EPS
;
return
(
rho_r
(
r
+
dr
)
-
rho_r
(
r
))
/
dr
;
}
// Approximates the third derivative of rho
double
CbPotential
::
rho_rrr
(
const
double
&
r
)
const
{
const
double
dr
=
r
*
EPS
;
return
(
rho_rr
(
r
+
dr
)
-
rho_rr
(
r
))
/
dr
;
}
// Approximates the derivative of the embedding function
double
CbPotential
::
F_p
(
const
double
&
p
)
const
{
const
double
dp
=
p
*
EPS
;
return
(
F
(
p
+
dp
)
-
F
(
p
))
/
dp
;
}
// Approximates the second derivative of the embedding function
double
CbPotential
::
F_pp
(
const
double
&
p
)
const
{
const
double
dp
=
p
*
EPS
;
return
(
F_p
(
p
+
dp
)
-
F_p
(
p
))
/
dp
;
}
// Approximates the third derivative of the embedding function
double
CbPotential
::
F_ppp
(
const
double
&
p
)
const
{
const
double
dp
=
p
*
EPS
;
return
(
F_pp
(
p
+
dp
)
-
F_pp
(
p
))
/
dp
;
}
// Approximates the derivative of phi3.
double
CbPotential
::
phi3_q
(
const
double
&
q
)
const
{
const
double
dq
=
q
*
EPS
;
return
(
phi3
(
q
+
dq
)
-
phi3
(
q
))
/
dq
;
}
// Approximates the second derivative of phi3.
double
CbPotential
::
phi3_qq
(
const
double
&
q
)
const
{
const
double
dq
=
q
*
EPS
;
return
(
phi3_q
(
q
+
dq
)
-
phi3_q
(
q
))
/
dq
;
}
// Compute bond angle jik from the squared length of vectors ij,ik,kj.
double
calculate_theta
(
double
ij2
,
double
ik2
,
double
jk2
)
{
return
acos
(
0.5
*
(
ik2
+
ij2
-
jk2
)
/
sqrt
(
ij2
*
ik2
)
);
}
// Initializes atomic interactions for up to three different terms.
Interactions
::
Interactions
(
int
a
,
int
b
,
int
c
)
{
// bitwise OR combines the terms that are listed
const
int
abc
=
a
|
b
|
c
;
pairwise
=
(
abc
&
PAIRWISE
)
>
0
;
embedding
=
(
abc
&
EAM
)
>
0
;
three_body
=
(
abc
&
THREE_BDY
)
>
0
;
angle_bending
=
(
abc
&
ANGLE_BND
)
>
0
;
}
}
Event Timeline
Log In to Comment