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35 #ifndef GMX_MULTIPLETIMESTEPPING_H
36 #define GMX_MULTIPLETIMESTEPPING_H
37
38 #include <bitset>
39
40 #include "gromacs/utility/arrayref.h"
41 #include "gromacs/utility/enumerationhelpers.h"
42
43 struct t_inputrec;
44
45 namespace gmx
46 {
47
48 //! Force group available for selection for multiple time step integration
49 enum class MtsForceGroups : int
50 {
51 LongrangeNonbonded, //!< PME-mesh or Ewald for electrostatics and/or LJ
52 Nonbonded, //!< Non-bonded pair interactions
53 Pair, //!< Bonded pair interactions
54 Dihedral, //!< Dihedrals, including cmap (not restraints)
55 Angle, //!< Bonded angle potentials (not restraints)
56 Pull, //!< COM pulling
57 Awh, //!< Accelerated weight histogram method
58 Count //!< The number of groups above
59 };
60
61 static const gmx::EnumerationArray<MtsForceGroups, std::string> mtsForceGroupNames = {
62 "longrange-nonbonded", "nonbonded", "pair", "dihedral", "angle", "pull", "awh"
63 };
64
65 //! Setting for a single level for multiple time step integration
66 struct MtsLevel
67 {
68 //! The force group selection for this level;
69 std::bitset<static_cast<int>(MtsForceGroups::Count)> forceGroups;
70 //! The factor between the base, fastest, time step and the time step for this level
71 int stepFactor;
72 };
73
74 /*! \brief Returns the MTS level at which a force group is to be computed
75 *
76 * \param[in] mtsLevels List of force groups for each MTS level, can be empty without MTS
77 * \param[in] mtsForceGroup The force group to query the MTS level for
78 */
forceGroupMtsLevel(ArrayRef<const MtsLevel> mtsLevels,const MtsForceGroups mtsForceGroup)79 static inline int forceGroupMtsLevel(ArrayRef<const MtsLevel> mtsLevels, const MtsForceGroups mtsForceGroup)
80 {
81 GMX_ASSERT(mtsLevels.empty() || mtsLevels.size() == 2, "Only 0 or 2 MTS levels are supported");
82
83 return (mtsLevels.empty() || mtsLevels[0].forceGroups[static_cast<int>(mtsForceGroup)]) ? 0 : 1;
84 };
85
86 /*! \brief Returns the interval in steps at which the non-bonded pair forces are calculated
87 *
88 * Note: returns 1 when multiple time-stepping is not activated.
89 */
90 int nonbondedMtsFactor(const t_inputrec& ir);
91
92 //! (Release) Asserts that all multiple time-stepping requirements on \p ir are fulfilled
93 void assertMtsRequirements(const t_inputrec& ir);
94
95 } // namespace gmx
96
97 #endif /* GMX_MULTIPLETIMESTEPPING_H */
98