Page Menu
Home
c4science
Search
Configure Global Search
Log In
Files
F81461384
pair_sw.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
Fri, Sep 6, 04:51
Size
17 KB
Mime Type
text/x-c
Expires
Sun, Sep 8, 04:51 (2 d)
Engine
blob
Format
Raw Data
Handle
20438571
Attached To
rLAMMPS lammps
pair_sw.cpp
View Options
/* ----------------------------------------------------------------------
LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
http://lammps.sandia.gov, Sandia National Laboratories
Steve Plimpton, sjplimp@sandia.gov
Copyright (2003) Sandia Corporation. Under the terms of Contract
DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains
certain rights in this software. This software is distributed under
the GNU General Public License.
See the README file in the top-level LAMMPS directory.
------------------------------------------------------------------------- */
/* ----------------------------------------------------------------------
Contributing author: Aidan Thompson (SNL)
------------------------------------------------------------------------- */
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "pair_sw.h"
#include "atom.h"
#include "neighbor.h"
#include "neigh_request.h"
#include "force.h"
#include "comm.h"
#include "memory.h"
#include "neighbor.h"
#include "neigh_list.h"
#include "memory.h"
#include "error.h"
using
namespace
LAMMPS_NS
;
#define MAXLINE 1024
#define DELTA 4
/* ---------------------------------------------------------------------- */
PairSW
::
PairSW
(
LAMMPS
*
lmp
)
:
Pair
(
lmp
)
{
single_enable
=
0
;
restartinfo
=
0
;
one_coeff
=
1
;
manybody_flag
=
1
;
nelements
=
0
;
elements
=
NULL
;
nparams
=
maxparam
=
0
;
params
=
NULL
;
elem2param
=
NULL
;
map
=
NULL
;
}
/* ----------------------------------------------------------------------
check if allocated, since class can be destructed when incomplete
------------------------------------------------------------------------- */
PairSW
::~
PairSW
()
{
if
(
copymode
)
return
;
if
(
elements
)
for
(
int
i
=
0
;
i
<
nelements
;
i
++
)
delete
[]
elements
[
i
];
delete
[]
elements
;
memory
->
destroy
(
params
);
memory
->
destroy
(
elem2param
);
if
(
allocated
)
{
memory
->
destroy
(
setflag
);
memory
->
destroy
(
cutsq
);
delete
[]
map
;
}
}
/* ---------------------------------------------------------------------- */
void
PairSW
::
compute
(
int
eflag
,
int
vflag
)
{
int
i
,
j
,
k
,
ii
,
jj
,
kk
,
inum
,
jnum
,
jnumm1
;
int
itype
,
jtype
,
ktype
,
ijparam
,
ikparam
,
ijkparam
;
tagint
itag
,
jtag
;
double
xtmp
,
ytmp
,
ztmp
,
delx
,
dely
,
delz
,
evdwl
,
fpair
;
double
rsq
,
rsq1
,
rsq2
;
double
delr1
[
3
],
delr2
[
3
],
fj
[
3
],
fk
[
3
];
int
*
ilist
,
*
jlist
,
*
numneigh
,
**
firstneigh
;
evdwl
=
0.0
;
if
(
eflag
||
vflag
)
ev_setup
(
eflag
,
vflag
);
else
evflag
=
vflag_fdotr
=
0
;
double
**
x
=
atom
->
x
;
double
**
f
=
atom
->
f
;
tagint
*
tag
=
atom
->
tag
;
int
*
type
=
atom
->
type
;
int
nlocal
=
atom
->
nlocal
;
int
newton_pair
=
force
->
newton_pair
;
inum
=
list
->
inum
;
ilist
=
list
->
ilist
;
numneigh
=
list
->
numneigh
;
firstneigh
=
list
->
firstneigh
;
// loop over full neighbor list of my atoms
for
(
ii
=
0
;
ii
<
inum
;
ii
++
)
{
i
=
ilist
[
ii
];
itag
=
tag
[
i
];
itype
=
map
[
type
[
i
]];
xtmp
=
x
[
i
][
0
];
ytmp
=
x
[
i
][
1
];
ztmp
=
x
[
i
][
2
];
// two-body interactions, skip half of them
jlist
=
firstneigh
[
i
];
jnum
=
numneigh
[
i
];
for
(
jj
=
0
;
jj
<
jnum
;
jj
++
)
{
j
=
jlist
[
jj
];
j
&=
NEIGHMASK
;
jtag
=
tag
[
j
];
if
(
itag
>
jtag
)
{
if
((
itag
+
jtag
)
%
2
==
0
)
continue
;
}
else
if
(
itag
<
jtag
)
{
if
((
itag
+
jtag
)
%
2
==
1
)
continue
;
}
else
{
if
(
x
[
j
][
2
]
<
ztmp
)
continue
;
if
(
x
[
j
][
2
]
==
ztmp
&&
x
[
j
][
1
]
<
ytmp
)
continue
;
if
(
x
[
j
][
2
]
==
ztmp
&&
x
[
j
][
1
]
==
ytmp
&&
x
[
j
][
0
]
<
xtmp
)
continue
;
}
jtype
=
map
[
type
[
j
]];
delx
=
xtmp
-
x
[
j
][
0
];
dely
=
ytmp
-
x
[
j
][
1
];
delz
=
ztmp
-
x
[
j
][
2
];
rsq
=
delx
*
delx
+
dely
*
dely
+
delz
*
delz
;
ijparam
=
elem2param
[
itype
][
jtype
][
jtype
];
if
(
rsq
>=
params
[
ijparam
].
cutsq
)
continue
;
twobody
(
&
params
[
ijparam
],
rsq
,
fpair
,
eflag
,
evdwl
);
f
[
i
][
0
]
+=
delx
*
fpair
;
f
[
i
][
1
]
+=
dely
*
fpair
;
f
[
i
][
2
]
+=
delz
*
fpair
;
f
[
j
][
0
]
-=
delx
*
fpair
;
f
[
j
][
1
]
-=
dely
*
fpair
;
f
[
j
][
2
]
-=
delz
*
fpair
;
if
(
evflag
)
ev_tally
(
i
,
j
,
nlocal
,
newton_pair
,
evdwl
,
0.0
,
fpair
,
delx
,
dely
,
delz
);
}
jnumm1
=
jnum
-
1
;
for
(
jj
=
0
;
jj
<
jnumm1
;
jj
++
)
{
j
=
jlist
[
jj
];
j
&=
NEIGHMASK
;
jtype
=
map
[
type
[
j
]];
ijparam
=
elem2param
[
itype
][
jtype
][
jtype
];
delr1
[
0
]
=
x
[
j
][
0
]
-
xtmp
;
delr1
[
1
]
=
x
[
j
][
1
]
-
ytmp
;
delr1
[
2
]
=
x
[
j
][
2
]
-
ztmp
;
rsq1
=
delr1
[
0
]
*
delr1
[
0
]
+
delr1
[
1
]
*
delr1
[
1
]
+
delr1
[
2
]
*
delr1
[
2
];
if
(
rsq1
>=
params
[
ijparam
].
cutsq
)
continue
;
for
(
kk
=
jj
+
1
;
kk
<
jnum
;
kk
++
)
{
k
=
jlist
[
kk
];
k
&=
NEIGHMASK
;
ktype
=
map
[
type
[
k
]];
ikparam
=
elem2param
[
itype
][
ktype
][
ktype
];
ijkparam
=
elem2param
[
itype
][
jtype
][
ktype
];
delr2
[
0
]
=
x
[
k
][
0
]
-
xtmp
;
delr2
[
1
]
=
x
[
k
][
1
]
-
ytmp
;
delr2
[
2
]
=
x
[
k
][
2
]
-
ztmp
;
rsq2
=
delr2
[
0
]
*
delr2
[
0
]
+
delr2
[
1
]
*
delr2
[
1
]
+
delr2
[
2
]
*
delr2
[
2
];
if
(
rsq2
>=
params
[
ikparam
].
cutsq
)
continue
;
threebody
(
&
params
[
ijparam
],
&
params
[
ikparam
],
&
params
[
ijkparam
],
rsq1
,
rsq2
,
delr1
,
delr2
,
fj
,
fk
,
eflag
,
evdwl
);
f
[
i
][
0
]
-=
fj
[
0
]
+
fk
[
0
];
f
[
i
][
1
]
-=
fj
[
1
]
+
fk
[
1
];
f
[
i
][
2
]
-=
fj
[
2
]
+
fk
[
2
];
f
[
j
][
0
]
+=
fj
[
0
];
f
[
j
][
1
]
+=
fj
[
1
];
f
[
j
][
2
]
+=
fj
[
2
];
f
[
k
][
0
]
+=
fk
[
0
];
f
[
k
][
1
]
+=
fk
[
1
];
f
[
k
][
2
]
+=
fk
[
2
];
if
(
evflag
)
ev_tally3
(
i
,
j
,
k
,
evdwl
,
0.0
,
fj
,
fk
,
delr1
,
delr2
);
}
}
}
if
(
vflag_fdotr
)
virial_fdotr_compute
();
}
/* ---------------------------------------------------------------------- */
void
PairSW
::
allocate
()
{
allocated
=
1
;
int
n
=
atom
->
ntypes
;
memory
->
create
(
setflag
,
n
+
1
,
n
+
1
,
"pair:setflag"
);
memory
->
create
(
cutsq
,
n
+
1
,
n
+
1
,
"pair:cutsq"
);
map
=
new
int
[
n
+
1
];
}
/* ----------------------------------------------------------------------
global settings
------------------------------------------------------------------------- */
void
PairSW
::
settings
(
int
narg
,
char
**
arg
)
{
if
(
narg
!=
0
)
error
->
all
(
FLERR
,
"Illegal pair_style command"
);
}
/* ----------------------------------------------------------------------
set coeffs for one or more type pairs
------------------------------------------------------------------------- */
void
PairSW
::
coeff
(
int
narg
,
char
**
arg
)
{
int
i
,
j
,
n
;
if
(
!
allocated
)
allocate
();
if
(
narg
!=
3
+
atom
->
ntypes
)
error
->
all
(
FLERR
,
"Incorrect args for pair coefficients"
);
// insure I,J args are * *
if
(
strcmp
(
arg
[
0
],
"*"
)
!=
0
||
strcmp
(
arg
[
1
],
"*"
)
!=
0
)
error
->
all
(
FLERR
,
"Incorrect args for pair coefficients"
);
// read args that map atom types to elements in potential file
// map[i] = which element the Ith atom type is, -1 if NULL
// nelements = # of unique elements
// elements = list of element names
if
(
elements
)
{
for
(
i
=
0
;
i
<
nelements
;
i
++
)
delete
[]
elements
[
i
];
delete
[]
elements
;
}
elements
=
new
char
*
[
atom
->
ntypes
];
for
(
i
=
0
;
i
<
atom
->
ntypes
;
i
++
)
elements
[
i
]
=
NULL
;
nelements
=
0
;
for
(
i
=
3
;
i
<
narg
;
i
++
)
{
if
(
strcmp
(
arg
[
i
],
"NULL"
)
==
0
)
{
map
[
i
-
2
]
=
-
1
;
continue
;
}
for
(
j
=
0
;
j
<
nelements
;
j
++
)
if
(
strcmp
(
arg
[
i
],
elements
[
j
])
==
0
)
break
;
map
[
i
-
2
]
=
j
;
if
(
j
==
nelements
)
{
n
=
strlen
(
arg
[
i
])
+
1
;
elements
[
j
]
=
new
char
[
n
];
strcpy
(
elements
[
j
],
arg
[
i
]);
nelements
++
;
}
}
// read potential file and initialize potential parameters
read_file
(
arg
[
2
]);
setup_params
();
// clear setflag since coeff() called once with I,J = * *
n
=
atom
->
ntypes
;
for
(
int
i
=
1
;
i
<=
n
;
i
++
)
for
(
int
j
=
i
;
j
<=
n
;
j
++
)
setflag
[
i
][
j
]
=
0
;
// set setflag i,j for type pairs where both are mapped to elements
int
count
=
0
;
for
(
int
i
=
1
;
i
<=
n
;
i
++
)
for
(
int
j
=
i
;
j
<=
n
;
j
++
)
if
(
map
[
i
]
>=
0
&&
map
[
j
]
>=
0
)
{
setflag
[
i
][
j
]
=
1
;
count
++
;
}
if
(
count
==
0
)
error
->
all
(
FLERR
,
"Incorrect args for pair coefficients"
);
}
/* ----------------------------------------------------------------------
init specific to this pair style
------------------------------------------------------------------------- */
void
PairSW
::
init_style
()
{
if
(
atom
->
tag_enable
==
0
)
error
->
all
(
FLERR
,
"Pair style Stillinger-Weber requires atom IDs"
);
if
(
force
->
newton_pair
==
0
)
error
->
all
(
FLERR
,
"Pair style Stillinger-Weber requires newton pair on"
);
// need a full neighbor list
int
irequest
=
neighbor
->
request
(
this
,
instance_me
);
neighbor
->
requests
[
irequest
]
->
half
=
0
;
neighbor
->
requests
[
irequest
]
->
full
=
1
;
}
/* ----------------------------------------------------------------------
init for one type pair i,j and corresponding j,i
------------------------------------------------------------------------- */
double
PairSW
::
init_one
(
int
i
,
int
j
)
{
if
(
setflag
[
i
][
j
]
==
0
)
error
->
all
(
FLERR
,
"All pair coeffs are not set"
);
return
cutmax
;
}
/* ---------------------------------------------------------------------- */
void
PairSW
::
read_file
(
char
*
file
)
{
int
params_per_line
=
14
;
char
**
words
=
new
char
*
[
params_per_line
+
1
];
memory
->
sfree
(
params
);
params
=
NULL
;
nparams
=
maxparam
=
0
;
// open file on proc 0
FILE
*
fp
;
if
(
comm
->
me
==
0
)
{
fp
=
force
->
open_potential
(
file
);
if
(
fp
==
NULL
)
{
char
str
[
128
];
sprintf
(
str
,
"Cannot open Stillinger-Weber potential file %s"
,
file
);
error
->
one
(
FLERR
,
str
);
}
}
// read each set of params from potential file
// one set of params can span multiple lines
// store params if all 3 element tags are in element list
int
n
,
nwords
,
ielement
,
jelement
,
kelement
;
char
line
[
MAXLINE
],
*
ptr
;
int
eof
=
0
;
while
(
1
)
{
if
(
comm
->
me
==
0
)
{
ptr
=
fgets
(
line
,
MAXLINE
,
fp
);
if
(
ptr
==
NULL
)
{
eof
=
1
;
fclose
(
fp
);
}
else
n
=
strlen
(
line
)
+
1
;
}
MPI_Bcast
(
&
eof
,
1
,
MPI_INT
,
0
,
world
);
if
(
eof
)
break
;
MPI_Bcast
(
&
n
,
1
,
MPI_INT
,
0
,
world
);
MPI_Bcast
(
line
,
n
,
MPI_CHAR
,
0
,
world
);
// strip comment, skip line if blank
if
((
ptr
=
strchr
(
line
,
'#'
)))
*
ptr
=
'\0'
;
nwords
=
atom
->
count_words
(
line
);
if
(
nwords
==
0
)
continue
;
// concatenate additional lines until have params_per_line words
while
(
nwords
<
params_per_line
)
{
n
=
strlen
(
line
);
if
(
comm
->
me
==
0
)
{
ptr
=
fgets
(
&
line
[
n
],
MAXLINE
-
n
,
fp
);
if
(
ptr
==
NULL
)
{
eof
=
1
;
fclose
(
fp
);
}
else
n
=
strlen
(
line
)
+
1
;
}
MPI_Bcast
(
&
eof
,
1
,
MPI_INT
,
0
,
world
);
if
(
eof
)
break
;
MPI_Bcast
(
&
n
,
1
,
MPI_INT
,
0
,
world
);
MPI_Bcast
(
line
,
n
,
MPI_CHAR
,
0
,
world
);
if
((
ptr
=
strchr
(
line
,
'#'
)))
*
ptr
=
'\0'
;
nwords
=
atom
->
count_words
(
line
);
}
if
(
nwords
!=
params_per_line
)
error
->
all
(
FLERR
,
"Incorrect format in Stillinger-Weber potential file"
);
// words = ptrs to all words in line
nwords
=
0
;
words
[
nwords
++
]
=
strtok
(
line
,
"
\t\n\r\f
"
);
while
((
words
[
nwords
++
]
=
strtok
(
NULL
,
"
\t\n\r\f
"
)))
continue
;
// ielement,jelement,kelement = 1st args
// if all 3 args are in element list, then parse this line
// else skip to next entry in file
for
(
ielement
=
0
;
ielement
<
nelements
;
ielement
++
)
if
(
strcmp
(
words
[
0
],
elements
[
ielement
])
==
0
)
break
;
if
(
ielement
==
nelements
)
continue
;
for
(
jelement
=
0
;
jelement
<
nelements
;
jelement
++
)
if
(
strcmp
(
words
[
1
],
elements
[
jelement
])
==
0
)
break
;
if
(
jelement
==
nelements
)
continue
;
for
(
kelement
=
0
;
kelement
<
nelements
;
kelement
++
)
if
(
strcmp
(
words
[
2
],
elements
[
kelement
])
==
0
)
break
;
if
(
kelement
==
nelements
)
continue
;
// load up parameter settings and error check their values
if
(
nparams
==
maxparam
)
{
maxparam
+=
DELTA
;
params
=
(
Param
*
)
memory
->
srealloc
(
params
,
maxparam
*
sizeof
(
Param
),
"pair:params"
);
}
params
[
nparams
].
ielement
=
ielement
;
params
[
nparams
].
jelement
=
jelement
;
params
[
nparams
].
kelement
=
kelement
;
params
[
nparams
].
epsilon
=
atof
(
words
[
3
]);
params
[
nparams
].
sigma
=
atof
(
words
[
4
]);
params
[
nparams
].
littlea
=
atof
(
words
[
5
]);
params
[
nparams
].
lambda
=
atof
(
words
[
6
]);
params
[
nparams
].
gamma
=
atof
(
words
[
7
]);
params
[
nparams
].
costheta
=
atof
(
words
[
8
]);
params
[
nparams
].
biga
=
atof
(
words
[
9
]);
params
[
nparams
].
bigb
=
atof
(
words
[
10
]);
params
[
nparams
].
powerp
=
atof
(
words
[
11
]);
params
[
nparams
].
powerq
=
atof
(
words
[
12
]);
params
[
nparams
].
tol
=
atof
(
words
[
13
]);
if
(
params
[
nparams
].
epsilon
<
0.0
||
params
[
nparams
].
sigma
<
0.0
||
params
[
nparams
].
littlea
<
0.0
||
params
[
nparams
].
lambda
<
0.0
||
params
[
nparams
].
gamma
<
0.0
||
params
[
nparams
].
biga
<
0.0
||
params
[
nparams
].
bigb
<
0.0
||
params
[
nparams
].
powerp
<
0.0
||
params
[
nparams
].
powerq
<
0.0
||
params
[
nparams
].
tol
<
0.0
)
error
->
all
(
FLERR
,
"Illegal Stillinger-Weber parameter"
);
nparams
++
;
}
delete
[]
words
;
}
/* ---------------------------------------------------------------------- */
void
PairSW
::
setup_params
()
{
int
i
,
j
,
k
,
m
,
n
;
double
rtmp
;
// set elem2param for all triplet combinations
// must be a single exact match to lines read from file
// do not allow for ACB in place of ABC
memory
->
destroy
(
elem2param
);
memory
->
create
(
elem2param
,
nelements
,
nelements
,
nelements
,
"pair:elem2param"
);
for
(
i
=
0
;
i
<
nelements
;
i
++
)
for
(
j
=
0
;
j
<
nelements
;
j
++
)
for
(
k
=
0
;
k
<
nelements
;
k
++
)
{
n
=
-
1
;
for
(
m
=
0
;
m
<
nparams
;
m
++
)
{
if
(
i
==
params
[
m
].
ielement
&&
j
==
params
[
m
].
jelement
&&
k
==
params
[
m
].
kelement
)
{
if
(
n
>=
0
)
error
->
all
(
FLERR
,
"Potential file has duplicate entry"
);
n
=
m
;
}
}
if
(
n
<
0
)
error
->
all
(
FLERR
,
"Potential file is missing an entry"
);
elem2param
[
i
][
j
][
k
]
=
n
;
}
// compute parameter values derived from inputs
// set cutsq using shortcut to reduce neighbor list for accelerated
// calculations. cut must remain unchanged as it is a potential parameter
// (cut = a*sigma)
for
(
m
=
0
;
m
<
nparams
;
m
++
)
{
params
[
m
].
cut
=
params
[
m
].
sigma
*
params
[
m
].
littlea
;
rtmp
=
params
[
m
].
cut
;
if
(
params
[
m
].
tol
>
0.0
)
{
if
(
params
[
m
].
tol
>
0.01
)
params
[
m
].
tol
=
0.01
;
if
(
params
[
m
].
gamma
<
1.0
)
rtmp
=
rtmp
+
params
[
m
].
gamma
*
params
[
m
].
sigma
/
log
(
params
[
m
].
tol
);
else
rtmp
=
rtmp
+
params
[
m
].
sigma
/
log
(
params
[
m
].
tol
);
}
params
[
m
].
cutsq
=
rtmp
*
rtmp
;
params
[
m
].
sigma_gamma
=
params
[
m
].
sigma
*
params
[
m
].
gamma
;
params
[
m
].
lambda_epsilon
=
params
[
m
].
lambda
*
params
[
m
].
epsilon
;
params
[
m
].
lambda_epsilon2
=
2.0
*
params
[
m
].
lambda
*
params
[
m
].
epsilon
;
params
[
m
].
c1
=
params
[
m
].
biga
*
params
[
m
].
epsilon
*
params
[
m
].
powerp
*
params
[
m
].
bigb
*
pow
(
params
[
m
].
sigma
,
params
[
m
].
powerp
);
params
[
m
].
c2
=
params
[
m
].
biga
*
params
[
m
].
epsilon
*
params
[
m
].
powerq
*
pow
(
params
[
m
].
sigma
,
params
[
m
].
powerq
);
params
[
m
].
c3
=
params
[
m
].
biga
*
params
[
m
].
epsilon
*
params
[
m
].
bigb
*
pow
(
params
[
m
].
sigma
,
params
[
m
].
powerp
+
1.0
);
params
[
m
].
c4
=
params
[
m
].
biga
*
params
[
m
].
epsilon
*
pow
(
params
[
m
].
sigma
,
params
[
m
].
powerq
+
1.0
);
params
[
m
].
c5
=
params
[
m
].
biga
*
params
[
m
].
epsilon
*
params
[
m
].
bigb
*
pow
(
params
[
m
].
sigma
,
params
[
m
].
powerp
);
params
[
m
].
c6
=
params
[
m
].
biga
*
params
[
m
].
epsilon
*
pow
(
params
[
m
].
sigma
,
params
[
m
].
powerq
);
}
// set cutmax to max of all params
cutmax
=
0.0
;
for
(
m
=
0
;
m
<
nparams
;
m
++
)
{
rtmp
=
sqrt
(
params
[
m
].
cutsq
);
if
(
rtmp
>
cutmax
)
cutmax
=
rtmp
;
}
}
/* ---------------------------------------------------------------------- */
void
PairSW
::
twobody
(
Param
*
param
,
double
rsq
,
double
&
fforce
,
int
eflag
,
double
&
eng
)
{
double
r
,
rinvsq
,
rp
,
rq
,
rainv
,
rainvsq
,
expsrainv
;
r
=
sqrt
(
rsq
);
rinvsq
=
1.0
/
rsq
;
rp
=
pow
(
r
,
-
param
->
powerp
);
rq
=
pow
(
r
,
-
param
->
powerq
);
rainv
=
1.0
/
(
r
-
param
->
cut
);
rainvsq
=
rainv
*
rainv
*
r
;
expsrainv
=
exp
(
param
->
sigma
*
rainv
);
fforce
=
(
param
->
c1
*
rp
-
param
->
c2
*
rq
+
(
param
->
c3
*
rp
-
param
->
c4
*
rq
)
*
rainvsq
)
*
expsrainv
*
rinvsq
;
if
(
eflag
)
eng
=
(
param
->
c5
*
rp
-
param
->
c6
*
rq
)
*
expsrainv
;
}
/* ---------------------------------------------------------------------- */
void
PairSW
::
threebody
(
Param
*
paramij
,
Param
*
paramik
,
Param
*
paramijk
,
double
rsq1
,
double
rsq2
,
double
*
delr1
,
double
*
delr2
,
double
*
fj
,
double
*
fk
,
int
eflag
,
double
&
eng
)
{
double
r1
,
rinvsq1
,
rainv1
,
gsrainv1
,
gsrainvsq1
,
expgsrainv1
;
double
r2
,
rinvsq2
,
rainv2
,
gsrainv2
,
gsrainvsq2
,
expgsrainv2
;
double
rinv12
,
cs
,
delcs
,
delcssq
,
facexp
,
facrad
,
frad1
,
frad2
;
double
facang
,
facang12
,
csfacang
,
csfac1
,
csfac2
;
r1
=
sqrt
(
rsq1
);
rinvsq1
=
1.0
/
rsq1
;
rainv1
=
1.0
/
(
r1
-
paramij
->
cut
);
gsrainv1
=
paramij
->
sigma_gamma
*
rainv1
;
gsrainvsq1
=
gsrainv1
*
rainv1
/
r1
;
expgsrainv1
=
exp
(
gsrainv1
);
r2
=
sqrt
(
rsq2
);
rinvsq2
=
1.0
/
rsq2
;
rainv2
=
1.0
/
(
r2
-
paramik
->
cut
);
gsrainv2
=
paramik
->
sigma_gamma
*
rainv2
;
gsrainvsq2
=
gsrainv2
*
rainv2
/
r2
;
expgsrainv2
=
exp
(
gsrainv2
);
rinv12
=
1.0
/
(
r1
*
r2
);
cs
=
(
delr1
[
0
]
*
delr2
[
0
]
+
delr1
[
1
]
*
delr2
[
1
]
+
delr1
[
2
]
*
delr2
[
2
])
*
rinv12
;
delcs
=
cs
-
paramijk
->
costheta
;
delcssq
=
delcs
*
delcs
;
facexp
=
expgsrainv1
*
expgsrainv2
;
// facrad = sqrt(paramij->lambda_epsilon*paramik->lambda_epsilon) *
// facexp*delcssq;
facrad
=
paramijk
->
lambda_epsilon
*
facexp
*
delcssq
;
frad1
=
facrad
*
gsrainvsq1
;
frad2
=
facrad
*
gsrainvsq2
;
facang
=
paramijk
->
lambda_epsilon2
*
facexp
*
delcs
;
facang12
=
rinv12
*
facang
;
csfacang
=
cs
*
facang
;
csfac1
=
rinvsq1
*
csfacang
;
fj
[
0
]
=
delr1
[
0
]
*
(
frad1
+
csfac1
)
-
delr2
[
0
]
*
facang12
;
fj
[
1
]
=
delr1
[
1
]
*
(
frad1
+
csfac1
)
-
delr2
[
1
]
*
facang12
;
fj
[
2
]
=
delr1
[
2
]
*
(
frad1
+
csfac1
)
-
delr2
[
2
]
*
facang12
;
csfac2
=
rinvsq2
*
csfacang
;
fk
[
0
]
=
delr2
[
0
]
*
(
frad2
+
csfac2
)
-
delr1
[
0
]
*
facang12
;
fk
[
1
]
=
delr2
[
1
]
*
(
frad2
+
csfac2
)
-
delr1
[
1
]
*
facang12
;
fk
[
2
]
=
delr2
[
2
]
*
(
frad2
+
csfac2
)
-
delr1
[
2
]
*
facang12
;
if
(
eflag
)
eng
=
facrad
;
}
Event Timeline
Log In to Comment