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37 * This implements molecule setup tests
39 * \author Victor Holanda <victor.holanda@cscs.ch>
40 * \author Joe Jordan <ejjordan@kth.se>
41 * \author Prashanth Kanduri <kanduri@cscs.ch>
42 * \author Sebastian Keller <keller@cscs.ch>
43 * \author Artem Zhmurov <zhmurov@gmail.com>
45 #include "nblib/integrator.h"
46 #include "gromacs/pbcutil/pbc.h"
47 #include "gromacs/utility/arrayref.h"
48 #include "nblib/molecules.h"
49 #include "nblib/particletype.h"
50 #include "nblib/simulationstate.h"
51 #include "nblib/topology.h"
53 #include "testutils/testasserts.h"
62 TEST(NBlibTest, IntegratorWorks)
68 ParticleType particleType(ParticleTypeName("H"), Mass(1.0));
69 Molecule molecule(MoleculeName("SomeMolecule"));
70 molecule.addParticle(ParticleName("SomeAtom"), particleType);
72 ParticleTypesInteractions interactions;
73 interactions.add(particleType.name(), C6{ 0 }, C12{ 0 });
75 TopologyBuilder topologyBuilder;
76 topologyBuilder.addMolecule(molecule, numAtoms);
77 topologyBuilder.addParticleTypesInteractions(interactions);
78 Topology topology = topologyBuilder.buildTopology();
80 std::vector<Vec3> x(numAtoms, { 0.0, 0.0, 0.0 });
81 std::vector<Vec3> v(numAtoms, { 0.0, 0.0, 0.0 });
82 std::vector<Vec3> f(numAtoms, { 1.0, 2.0, 0.0 });
86 std::vector<Vec3> x0(x);
87 std::vector<Vec3> v0(v);
89 SimulationState simulationState(x, v, f, box, topology);
90 put_atoms_in_box(PbcType::Xyz, box.legacyMatrix(), x0);
92 LeapFrog integrator(simulationState.topology(), simulationState.box());
94 gmx::test::FloatingPointTolerance tolerance = gmx::test::absoluteTolerance(numSteps * 0.000005);
95 for (int step = 0; step < numSteps; step++)
97 real totalTime = step * dt;
102 for (int i = 0; i < numAtoms; i++)
104 for (int d = 0; d < dimSize; d++)
106 // Analytical solution for constant-force particle movement
107 int typeIndex = simulationState.topology().getParticleTypeIdOfAllParticles()[i];
108 real im = 1.0 / simulationState.topology().getParticleTypes()[typeIndex].mass();
110 x0[i][d] + v0[i][d] * totalTime + 0.5 * f[i][d] * totalTime * totalTime * im;
111 vAnalytical[d] = v0[i][d] + f[i][d] * totalTime * im;
113 EXPECT_REAL_EQ_TOL(xAnalytical[d], simulationState.coordinates()[i][d], tolerance)
115 "Coordinate {} of atom {} is different from analytical solution "
121 EXPECT_REAL_EQ_TOL(vAnalytical[d], simulationState.velocities()[i][d], tolerance)
123 "Velocity component {} of atom {} is different from analytical "
124 "solution at step {}.",
129 integrator.integrate(dt,
130 simulationState.coordinates(),
131 simulationState.velocities(),
132 simulationState.forces());