ViewVC Help
View File | Revision Log | Show Annotations | View Changeset | Root Listing
root/group/trunk/OOPSE/libmdtools/Bond.cpp
Revision: 610
Committed: Tue Jul 15 15:50:55 2003 UTC (20 years, 11 months ago) by gezelter
File size: 1550 byte(s)
Log Message:
more archaic code fixes

File Contents

# User Rev Content
1 mmeineke 377 #include "SRI.hpp"
2     #include "Atom.hpp"
3     #include <math.h>
4     #include <iostream>
5     #include <stdlib.h>
6    
7    
8    
9     Bond::Bond(){
10    
11     c_constraint = NULL;
12     c_is_constrained = 0;
13     }
14    
15     void Bond::set_atoms( Atom &a, Atom &b ){
16    
17     c_p_a = &a;
18     c_p_b = &b;
19     }
20    
21     void Bond::constrain(double bond_distance){
22    
23     double dsqr = bond_distance * bond_distance;
24    
25     c_is_constrained = 1;
26    
27     c_constraint = new Constraint();
28     c_constraint->set_a( c_p_a->getIndex() );
29     c_constraint->set_b( c_p_b->getIndex() );
30     c_constraint->set_dsqr( dsqr );
31     }
32    
33     Bond::~Bond(){
34     delete c_constraint;
35     c_constraint = 0;
36     }
37    
38     void Bond::calc_forces(){
39    
40     /* return 0 if the bond is constrained and stop wasting cpu */
41    
42     if(c_is_constrained){
43    
44     c_potential_E = 0.0;
45     return;
46     }
47    
48     vect r_ab; /*the vector whose origin is a and end is b */
49     double force; /* the force scaling factor. */
50     double Fab_x; /*the x,y, and z components of the force */
51     double Fab_y;
52     double Fab_z;
53    
54     /* initialize the vector */
55    
56     r_ab.x = c_p_b->getX() - c_p_a->getX();
57     r_ab.y = c_p_b->getY() - c_p_a->getY();
58     r_ab.z = c_p_b->getZ() - c_p_a->getZ();
59     r_ab.length = sqrt((r_ab.x * r_ab.x + r_ab.y * r_ab.y + r_ab.z * r_ab.z));
60    
61     /* calculate the force here */
62    
63     force = bond_force(r_ab.length);
64    
65     Fab_x = -force * r_ab.x / r_ab.length;
66     Fab_y = -force * r_ab.y / r_ab.length;
67     Fab_z = -force * r_ab.z / r_ab.length;
68    
69     c_p_a->addFx(Fab_x);
70     c_p_a->addFy(Fab_y);
71     c_p_a->addFz(Fab_z);
72    
73     c_p_b->addFx(-Fab_x);
74     c_p_b->addFy(-Fab_y);
75     c_p_b->addFz(-Fab_z);
76    
77     return;
78     }