1 //
2 // bem.h
3 //
4 // Copyright (C) 1996 Limit Point Systems, Inc.
5 //
6 // Author: Curtis Janssen <cljanss@limitpt.com>
7 // Maintainer: LPS
8 //
9 // This file is part of the SC Toolkit.
10 //
11 // The SC Toolkit is free software; you can redistribute it and/or modify
12 // it under the terms of the GNU Library General Public License as published by
13 // the Free Software Foundation; either version 2, or (at your option)
14 // any later version.
15 //
16 // The SC Toolkit is distributed in the hope that it will be useful,
17 // but WITHOUT ANY WARRANTY; without even the implied warranty of
18 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
19 // GNU Library General Public License for more details.
20 //
21 // You should have received a copy of the GNU Library General Public License
22 // along with the SC Toolkit; see the file COPYING.LIB.  If not, write to
23 // the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
24 //
25 // The U.S. Government is granted a limited license as per AL 91-7.
26 //
27 
28 #ifndef _chemistry_solvent_bem_h
29 #define _chemistry_solvent_bem_h
30 
31 #include <util/class/class.h>
32 #include <util/state/state.h>
33 #include <util/keyval/keyval.h>
34 #include <math/isosurf/volume.h>
35 #include <math/isosurf/surf.h>
36 #include <math/scmat/matrix.h>
37 #include <chemistry/molecule/molecule.h>
38 
39 namespace sc {
40 
41 // This represents a solvent by a polarization charge on a dielectric
42 // boundary surface.
43 class BEMSolvent: public DescribedClass {
44   private:
45     int debug_;
46 
47     Ref<Molecule> solute_;
48     Ref<Molecule> solvent_;
49     double solvent_density_;
50     double dielectric_constant_;
51     Ref<SCMatrixKit> matrixkit_;
52     RefSCMatrix system_matrix_i_;
53     double f_;
54     Ref<MessageGrp> grp_;
55 
56     double area_;
57     double volume_;
58     double computed_enclosed_charge_;
59     double edisp_;
60     double erep_;
61 
62     Ref<TriangulatedImplicitSurface> surf_;
63 
64     double** alloc_array(int n, int m);
65     void free_array(double**);
66 
67     // This holds the area associated with each vertex.  It is used
68     // to convert charges to charge densities and back.
69     double* vertex_area_;
70 
71     // Given charges compute surface charge density.
72     void charges_to_surface_charge_density(double *charges);
73 
74     // Given surface charge density compute charges.
75     void surface_charge_density_to_charges(double *charges);
76   public:
77     BEMSolvent(const Ref<KeyVal>&);
78     virtual ~BEMSolvent();
79 
80     // This should be called after everything is setup--the
81     // molecule has the correct the geometry and all of the
82     // parameters have been adjusted.
83     void init();
84     // This gets rid of the system matrix inverse and, optionally, the surface.
85     void done(int clear_surface = 1);
86 
ncharge()87     int ncharge() { return surf_->nvertex(); }
88 
solvent()89     Ref<Molecule> solvent() { return solvent_ ;}
solvent_density()90     double solvent_density() { return solvent_density_ ;}
91 
92     // NOTE: call allocation routines after init and free routines before done
alloc_charge_positions()93     double** alloc_charge_positions() { return alloc_array(ncharge(), 3); }
free_charge_positions(double ** a)94     void free_charge_positions(double**a) { free_array(a); }
95 
alloc_normals()96     double** alloc_normals()  { return alloc_array(ncharge(), 3); }
free_normals(double ** a)97     void free_normals(double**a) { free_array(a); }
98 
alloc_efield_dot_normals()99     double* alloc_efield_dot_normals()  { return new double[ncharge()]; }
free_efield_dot_normals(double * a)100     void free_efield_dot_normals(double*a) { delete[] a; }
101 
alloc_charges()102     double* alloc_charges() { return new double[ncharge()]; }
free_charges(double * a)103     void free_charges(double*a) { delete[] a; }
104 
105     void charge_positions(double**);
106     void normals(double**);
107 
108     // Given the efield dotted with the normals at the charge positions this
109     // will compute a new set of charges.
110     void compute_charges(double* efield_dot_normals, double* charge);
111 
112     // Given a set of charges and a total charge, this will normalize
113     // the integrated charge to the charge that would be expected on
114     // the surface if the given total charge were enclosed within it.
115     void normalize_charge(double enclosed_charge, double* charges);
116 
117     // Given charges and nuclear charges compute their interation energy.
118     double nuclear_charge_interaction_energy(double *nuclear_charge,
119                                              double** charge_positions,
120                                              double* charge);
121 
122     // Given charges compute the interaction energy between the nuclei
123     // and the point charges.
124     double nuclear_interaction_energy(double** charge_positions,
125                                       double* charge);
126 
127     // Given charges compute the interaction energy for just the surface.
128     double self_interaction_energy(double** charge_positions, double *charge);
129 
130     // Given the charges, return the total polarization charge on the surface.
131     double polarization_charge(double* charge);
132 
133     // Return the area (available after compute_charges called).
area()134     double area() const { return area_; }
135     // Return the volume (available after compute_charges called).
volume()136     double volume() const { return volume_; }
137     // Return the enclosed charge (available after compute_charges called).
computed_enclosed_charge()138     double computed_enclosed_charge() const {
139       return computed_enclosed_charge_;
140     }
141 
disp()142     double disp() {return edisp_;}
rep()143     double rep()  {return erep_;}
144     double disprep();
145 
146     // this never needs to be called explicitly, but is here now for debugging
147     void init_system_matrix();
148 
surface()149     Ref<TriangulatedImplicitSurface> surface() const { return surf_; }
150 
matrixkit()151     Ref<SCMatrixKit> matrixkit() { return matrixkit_; }
152 };
153 
154 }
155 
156 #endif
157 
158 // Local Variables:
159 // mode: c++
160 // c-file-style: "CLJ"
161 // End:
162