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37 /*! \libinternal \file
38 * \brief Declares interface to constraint code.
40 * \author Berk Hess <hess@kth.se>
41 * \author Mark Abraham <mark.j.abraham@gmail.com>
42 * \ingroup module_mdlib
46 #ifndef GMX_MDLIB_CONSTR_H
47 #define GMX_MDLIB_CONSTR_H
51 #include "gromacs/math/vectypes.h"
52 #include "gromacs/topology/idef.h"
53 #include "gromacs/utility/arrayref.h"
54 #include "gromacs/utility/basedefinitions.h"
55 #include "gromacs/utility/classhelpers.h"
56 #include "gromacs/utility/gmxassert.h"
57 #include "gromacs/utility/real.h"
60 struct gmx_localtop_t;
63 struct gmx_multisim_t;
77 template <typename T> class ArrayRefWithPadding;
79 //! Describes supported flavours of constrained updates.
80 enum class ConstraintVariable : int
82 Positions, /* Constrain positions (mass weighted) */
83 Velocities, /* Constrain velocities (mass weighted) */
84 Derivative, /* Constrain a derivative (mass weighted), *
85 * for instance velocity or acceleration, *
86 * constraint virial can not be calculated. */
87 Deriv_FlexCon, /* As Derivative, but only output flex. con. */
88 Force, /* Constrain forces (non mass-weighted) */
89 // TODO What does this do? Improve the comment.
90 ForceDispl /* Like Force, but free particles will have mass
91 * 1 and frozen particles mass 0 */
95 * \brief Handles constraints */
99 /*! \brief Constructor
101 * Private to enforce use of makeConstraints() factory
103 Constraints(const gmx_mtop_t &mtop,
104 const t_inputrec &ir,
109 const gmx_multisim_t *ms,
111 gmx_wallcycle *wcycle,
112 bool pbcHandlingRequired,
116 /*! \brief This member type helps implement a factory
117 * function, because its objects can access the private
119 struct CreationHelper;
123 /*! \brief Returns the total number of flexible constraints in the system. */
124 int numFlexibleConstraints() const;
126 /*! \brief Returns whether the system contains perturbed constraints */
127 bool havePerturbedConstraints() const;
129 /*! \brief Set up all the local constraints for the domain.
131 * \todo Make this a callback that is called automatically
132 * once a new domain has been made. */
133 void setConstraints(const gmx_localtop_t &top,
134 const t_mdatoms &md);
136 /*! \brief Applies constraints to coordinates.
138 * When econq=ConstraintVariable::Positions constrains
139 * coordinates xprime using th directions in x, min_proj is
142 * When econq=ConstraintVariable::Derivative, calculates the
143 * components xprime in the constraint directions and
144 * subtracts these components from min_proj. So when
145 * min_proj=xprime, the constraint components are projected
148 * When econq=ConstraintVariable::Deriv_FlexCon, the same is
149 * done as with ConstraintVariable::Derivative, but only the
150 * components of the flexible constraints are stored.
152 * delta_step is used for determining the constraint reference lengths
153 * when lenA != lenB or will the pull code with a pulling rate.
154 * step + delta_step is the step at which the final configuration
155 * is meant to be; for update delta_step = 1.
157 * step_scaling can be used to update coordinates based on the time
158 * step multiplied by this factor. Thus, normally 1.0 is passed. The
159 * SD1 integrator uses 0.5 in one of its calls, to correct positions
160 * for half a step of changed velocities.
162 * If v!=NULL also constrain v by adding the constraint corrections / dt.
164 * If vir!=NULL calculate the constraint virial.
166 * Return whether the application of constraints succeeded without error.
168 bool apply(bool bLog,
181 ConstraintVariable econq);
182 //! Links the essentialdynamics and constraint code.
183 void saveEdsamPointer(gmx_edsam *ed);
184 //! Getter for use by domain decomposition.
185 ArrayRef<const t_blocka> atom2constraints_moltype() const;
186 //! Getter for use by domain decomposition.
187 ArrayRef < const std::vector < int>> atom2settle_moltype() const;
189 /*! \brief Return the data for reduction for determining
190 * constraint RMS relative deviations, or an empty ArrayRef
191 * when not supported for any active constraints. */
192 ArrayRef<real> rmsdData() const;
193 /*! \brief Return the RMSD of the constraints when available. */
197 //! Implementation type.
199 //! Implementation object.
200 PrivateImplPointer<Impl> impl_;
203 /*! \brief Generate a fatal error because of too many LINCS/SETTLE warnings. */
204 [[ noreturn ]] void too_many_constraint_warnings(int eConstrAlg, int warncount);
206 /*! \brief Returns whether constraint with parameter \p iparamsIndex is a flexible constraint */
207 static inline bool isConstraintFlexible(const t_iparams *iparams,
210 GMX_ASSERT(iparams != nullptr, "Need a valid iparams array");
212 return (iparams[iparamsIndex].constr.dA == 0 &&
213 iparams[iparamsIndex].constr.dB == 0);
216 /* The at2con t_blocka struct returned by the routines below
217 * contains a list of constraints per atom.
218 * The F_CONSTRNC constraints in this structure number consecutively
219 * after the F_CONSTR constraints.
222 /*! \brief Tells make_at2con how to treat flexible constraints */
223 enum class FlexibleConstraintTreatment
225 Include, //!< Include all flexible constraints
226 Exclude //!< Exclude all flexible constraints
229 /*! \brief Returns the flexible constraint treatment depending on whether the integrator is dynamic */
230 FlexibleConstraintTreatment
231 flexibleConstraintTreatment(bool haveDynamicsIntegrator);
233 /*! \brief Returns a block struct to go from atoms to constraints
235 * The block struct will contain constraint indices with lower indices
236 * directly matching the order in F_CONSTR and higher indices matching
237 * the order in F_CONSTRNC offset by the number of constraints in F_CONSTR.
239 * \param[in] moltype The molecule data
240 * \param[in] iparams Interaction parameters, can be null when flexibleConstraintTreatment=Include
241 * \param[in] flexibleConstraintTreatment The flexible constraint treatment, see enum above
242 * \returns a block struct with all constraints for each atom
244 t_blocka make_at2con(const gmx_moltype_t &moltype,
245 gmx::ArrayRef<const t_iparams> iparams,
246 FlexibleConstraintTreatment flexibleConstraintTreatment);
248 /*! \brief Returns a block struct to go from atoms to constraints
250 * The block struct will contain constraint indices with lower indices
251 * directly matching the order in F_CONSTR and higher indices matching
252 * the order in F_CONSTRNC offset by the number of constraints in F_CONSTR.
254 * \param[in] numAtoms The number of atoms to construct the list for
255 * \param[in] ilist Interaction list, size F_NRE
256 * \param[in] iparams Interaction parameters, can be null when flexibleConstraintTreatment=Include
257 * \param[in] flexibleConstraintTreatment The flexible constraint treatment, see enum above
258 * \returns a block struct with all constraints for each atom
260 t_blocka make_at2con(int numAtoms,
261 const t_ilist *ilist,
262 const t_iparams *iparams,
263 FlexibleConstraintTreatment flexibleConstraintTreatment);
265 /*! \brief Returns an array of atom to constraints lists for the moltypes */
266 const t_blocka *atom2constraints_moltype(const Constraints *constr);
268 //! Return the number of flexible constraints in the \c ilist and \c iparams.
269 int countFlexibleConstraints(const t_ilist *ilist,
270 const t_iparams *iparams);
272 /*! \brief Returns the constraint iatoms for a constraint number con
273 * which comes from a list where F_CONSTR and F_CONSTRNC constraints
274 * are concatenated. */
276 constr_iatomptr(gmx::ArrayRef<const int> iatom_constr,
277 gmx::ArrayRef<const int> iatom_constrnc,
280 if (con*3 < iatom_constr.ssize())
282 return iatom_constr.data() + con*3;
286 return iatom_constrnc.data() + con*3 - iatom_constr.size();
290 /*! \brief Returns whether there are inter charge group constraints */
291 bool inter_charge_group_constraints(const gmx_mtop_t &mtop);
293 /*! \brief Returns whether there are inter charge group settles */
294 bool inter_charge_group_settles(const gmx_mtop_t &mtop);
296 /*! \brief Constrain the initial coordinates and velocities */
297 void do_constrain_first(FILE *log, gmx::Constraints *constr,
298 const t_inputrec *inputrec, const t_mdatoms *md,
300 ArrayRefWithPadding<RVec> x,
301 ArrayRefWithPadding<RVec> v,