void integrate_vv(int n_steps, int reuse_forces)
{
/* Prepare the Integrator */
on_integration_start();
#ifdef IMMERSED_BOUNDARY
// Here we initialize volume conservation
// This function checks if the reference volumes have been set and if necessary calculates them
IBM_InitVolumeConservation();
#endif
/* if any method vetoes (P3M not initialized), immediately bail out */
if (check_runtime_errors())
return;
/* Verlet list criterion */
skin2 = SQR(0.5 * skin);
INTEG_TRACE(fprintf(stderr,"%d: integrate_vv: integrating %d steps (recalc_forces=%d)\n",
this_node, n_steps, recalc_forces));
/* Integration Step: Preparation for first integration step:
Calculate forces f(t) as function of positions p(t) ( and velocities v(t) ) */
/* reuse_forces logic:
-1: recalculate forces unconditionally, mostly used for timing
0: recalculate forces if recalc_forces is set, meaning it is probably necessary
1: do not recalculate forces. Mostly when reading checkpoints with forces
*/
if (reuse_forces == -1 || (recalc_forces && reuse_forces != 1)) {
thermo_heat_up();
#ifdef LB
transfer_momentum = 0;
if (lattice_switch & LATTICE_LB && this_node == 0)
if (warnings) fprintf (stderr, "Warning: Recalculating forces, so the LB coupling forces are not included in the particle force the first time step. This only matters if it happens frequently during sampling.\n");
#endif
#ifdef LB_GPU
transfer_momentum_gpu = 0;
if (lattice_switch & LATTICE_LB_GPU && this_node == 0)
if (warnings) fprintf (stderr, "Warning: Recalculating forces, so the LB coupling forces are not included in the particle force the first time step. This only matters if it happens frequently during sampling.\n");
#endif
force_calc();
if(integ_switch != INTEG_METHOD_STEEPEST_DESCENT) {
rescale_forces();
#ifdef ROTATION
convert_initial_torques();
#endif
}
thermo_cool_down();
}
#ifdef GHMC
if(thermo_switch & THERMO_GHMC)
ghmc_init();
#endif
if (check_runtime_errors())
return;
n_verlet_updates = 0;
/* Integration loop */
for (int step=0; step<n_steps; step++) {
INTEG_TRACE(fprintf(stderr,"%d: STEP %d\n", this_node, step));
#ifdef BOND_CONSTRAINT
save_old_pos();
#endif
#ifdef GHMC
if(thermo_switch & THERMO_GHMC) {
if (step % ghmc_nmd == 0)
ghmc_momentum_update();
}
#endif
/* Integration Steps: Step 1 and 2 of Velocity Verlet scheme:
v(t+0.5*dt) = v(t) + 0.5*dt * f(t)
p(t + dt) = p(t) + dt * v(t+0.5*dt)
NOTE 1: Prefactors do not occur in formulas since we use
rescaled forces and velocities.
NOTE 2: Depending on the integration method Step 1 and Step 2
cannot be combined for the translation.
*/
if (integ_switch == INTEG_METHOD_NPT_ISO || nemd_method != NEMD_METHOD_OFF) {
propagate_vel();
propagate_pos();
} else if(integ_switch == INTEG_METHOD_STEEPEST_DESCENT) {
if(steepest_descent_step())
break;
} else {
propagate_vel_pos();
}
#ifdef BOND_CONSTRAINT
/**Correct those particle positions that participate in a rigid/constrained bond */
cells_update_ghosts();
correct_pos_shake();
#endif
#ifdef ELECTROSTATICS
if(coulomb.method == COULOMB_MAGGS) {
maggs_propagate_B_field(0.5*time_step);
}
#endif
#ifdef NPT
if (check_runtime_errors())
break;
#endif
/* Integration Step: Step 3 of Velocity Verlet scheme:
Calculate f(t+dt) as function of positions p(t+dt) ( and velocities v(t+0.5*dt) ) */
#ifdef LB
transfer_momentum = 1;
#endif
#ifdef LB_GPU
transfer_momentum_gpu = 1;
#endif
force_calc();
// IMMERSED_BOUNDARY
#ifdef IMMERSED_BOUNDARY
// Now the forces are computed and need to go into the LB fluid
if (lattice_switch & LATTICE_LB) IBM_ForcesIntoFluid_CPU();
#ifdef LB_GPU
if (lattice_switch & LATTICE_LB_GPU) IBM_ForcesIntoFluid_GPU();
#endif
#endif
#ifdef CATALYTIC_REACTIONS
integrate_reaction();
#endif
if (check_runtime_errors())
break;
/* Integration Step: Step 4 of Velocity Verlet scheme:
v(t+dt) = v(t+0.5*dt) + 0.5*dt * f(t+dt) */
if(integ_switch != INTEG_METHOD_STEEPEST_DESCENT) {
rescale_forces_propagate_vel();
#ifdef ROTATION
convert_torques_propagate_omega();
#endif
}
// SHAKE velocity updates
#ifdef BOND_CONSTRAINT
ghost_communicator(&cell_structure.update_ghost_pos_comm);
correct_vel_shake();
#endif
//VIRTUAL_SITES update vel
#ifdef VIRTUAL_SITES
ghost_communicator(&cell_structure.update_ghost_pos_comm);
update_mol_vel();
if (check_runtime_errors()) break;
#endif
// progagate one-step functionalities
#ifdef LB
if (lattice_switch & LATTICE_LB)
lattice_boltzmann_update();
if (check_runtime_errors())
break;
#endif
#ifdef LB_GPU
if(this_node == 0){
#ifdef ELECTROKINETICS
if (ek_initialized) {
ek_integrate();
}
else {
#endif
if (lattice_switch & LATTICE_LB_GPU)
lattice_boltzmann_update_gpu();
#ifdef ELECTROKINETICS
}
#endif
}
#endif //LB_GPU
// IMMERSED_BOUNDARY
#ifdef IMMERSED_BOUNDARY
IBM_UpdateParticlePositions();
// We reset all since otherwise the halo nodes may not be reset
// NB: the normal Espresso reset is also done after applying the forces
// if (lattice_switch & LATTICE_LB) IBM_ResetLBForces_CPU();
#ifdef LB_GPU
//if (lattice_switch & LATTICE_LB_GPU) IBM_ResetLBForces_GPU();
#endif
if (check_runtime_errors()) break;
// Ghost positions are now out-of-date
// We should update.
// Actually we seem to get the same results whether we do this here or not, but it is safer to do it
ghost_communicator(&cell_structure.update_ghost_pos_comm);
#endif // IMMERSED_BOUNDARY
#ifdef ELECTROSTATICS
if(coulomb.method == COULOMB_MAGGS) {
maggs_propagate_B_field(0.5*time_step);
}
#endif
#ifdef NPT
if((this_node==0) && (integ_switch == INTEG_METHOD_NPT_ISO))
nptiso.p_inst_av += nptiso.p_inst;
#endif
#ifdef GHMC
if(thermo_switch & THERMO_GHMC) {
if (step % ghmc_nmd == ghmc_nmd-1)
ghmc_mc();
}
#endif
if(integ_switch != INTEG_METHOD_STEEPEST_DESCENT) {
/* Propagate time: t = t+dt */
sim_time += time_step;
}
}
/* verlet list statistics */
if(n_verlet_updates>0) verlet_reuse = n_steps/(double) n_verlet_updates;
else verlet_reuse = 0;
#ifdef NPT
if(integ_switch == INTEG_METHOD_NPT_ISO) {
nptiso.invalidate_p_vel = 0;
MPI_Bcast(&nptiso.p_inst, 1, MPI_DOUBLE, 0, comm_cart);
MPI_Bcast(&nptiso.p_diff, 1, MPI_DOUBLE, 0, comm_cart);
MPI_Bcast(&nptiso.volume, 1, MPI_DOUBLE, 0, comm_cart);
if(this_node==0) nptiso.p_inst_av /= 1.0*n_steps;
MPI_Bcast(&nptiso.p_inst_av, 1, MPI_DOUBLE, 0, comm_cart);
}
#endif
#ifdef GHMC
if(thermo_switch & THERMO_GHMC)
ghmc_close();
#endif
}
void integrate_sd(int n_steps)
{
/* Prepare the Integrator */
on_integration_start();
/* if any method vetoes (P3M not initialized), immediately bail out */
if (check_runtime_errors())
return;
INTEG_TRACE(fprintf(stderr,"%d: integrate_vv: integrating %d steps (recalc_forces=%d)\n",
this_node, n_steps, recalc_forces));
/* Integration Step:
Calculate forces f(t) as function of positions p(t) ( and velocities v(t) ) */
//if (recalc_forces) {
//thermo_heat_up();
ghost_communicator(&cell_structure.collect_ghost_force_comm);
#ifdef ROTATION
convert_initial_torques();
#endif
//thermo_cool_down();
/* Communication Step: ghost forces */
/*apply trap forces to trapped molecules*/
#ifdef MOLFORCES
// prob. works only with harmonic bounds
calc_and_apply_mol_constraints();
#endif
/* should be pretty late, since it needs to zero out the total force */
#ifdef COMFIXED
calc_comfixed();
#endif
//rescale_forces();
#ifdef COLLISION_DETECTION
//should not be neccessery, as integrator avoids collision
handle_collisions();
#endif
// end of force calculation
#ifdef GHMC
if(thermo_switch & THERMO_GHMC)
ghmc_init();
#endif
if (check_runtime_errors())
return;
n_verlet_updates = 0;
/* Integration loop */
for(int step=0;step<n_steps;step++) {
INTEG_TRACE(fprintf(stderr,"%d: STEP %d\n",this_node,step));
//sd_set_particles_apart();
#ifdef BOND_CONSTRAINT
save_old_pos();
#endif
#ifdef GHMC
if(thermo_switch & THERMO_GHMC) {
if (step % ghmc_nmd == 0)
ghmc_momentum_update();
}
#endif
if(thermo_switch & ~(THERMO_SD|THERMO_BD) ){
static bool warned_thermo_sd_other=false;
if (!warned_thermo_sd_other){
fprintf (stderr, "Warning, using another thermo than the one provided by StokesDynamics breaks (most likely) StokesDynamics.\n");
warned_thermo_sd_other=true;
}
}
if (thermo_switch & THERMO_SD && thermo_switch &THERMO_BD) {
fprintf (stderr, "Warning: cannot use BD and SD. Disabeling BD!\n");
thermo_switch &= ~THERMO_BD;
}
/* Integration Step: Step 3 of Velocity Verlet scheme:
Calculate f(t) as function of positions p(t) ( and ``velocities'' v(t) ) */
#ifdef LB
transfer_momentum = 1;
#endif
#ifdef LB_GPU
transfer_momentum_gpu = 1;
#endif
force_calc();
#ifdef CATALYTIC_REACTIONS
integrate_reaction();
#endif
if (check_runtime_errors())
break;
#ifdef LB
if (lattice_switch & LATTICE_LB)
lattice_boltzmann_update();
if (check_runtime_errors())
break;
#endif
#ifdef LB_GPU
if(this_node == 0){
#ifdef ELECTROKINETICS
if (ek_initialized) {
ek_integrate();
}
else {
#endif
if (lattice_switch & LATTICE_LB_GPU)
lattice_boltzmann_update_gpu();
#ifdef ELECTROKINETICS
}
#endif
}
#endif //LB_GPU
#ifdef ELECTROSTATICS
if(coulomb.method == COULOMB_MAGGS) {
maggs_propagate_B_field(0.5*time_step);
}
#endif
#ifdef NPT
if((this_node==0) && (integ_switch == INTEG_METHOD_NPT_ISO))
nptiso.p_inst_av += nptiso.p_inst;
#endif
#ifdef GHMC
if(thermo_switch & THERMO_GHMC) {
if (step % ghmc_nmd == ghmc_nmd-1)
ghmc_mc();
}
#endif
/** Integration Steps: Update the Positions
\[ p_i(t + dt) = p_i(t) + dt * \mu_{ij} * f_j(t) + dt * \mu_{ij} * f^B_j \]
*/
propagate_pos_sd(); // we dont have velocities
#ifdef BOND_CONSTRAINT
static bool bond_constraint_with_sd_warned=false;
if (!bond_constraint_with_sd_warned){ // warn only once
fprintf (stderr, "Warning, using BOND_CONSTRAINT with StokesDynamics might not work as expected!.\n");
bond_constraint_with_sd_warned=true;
}
/**Correct those particle positions that participate in a rigid/constrained bond */
cells_update_ghosts();
correct_pos_shake();
#endif
#ifdef ELECTROSTATICS
if(coulomb.method == COULOMB_MAGGS) {
maggs_propagate_B_field(0.5*time_step);
}
#endif
#ifdef NPT
if (check_runtime_errors())
break;
#endif
/* Propagate time: t = t+dt */
sim_time += time_step;
}
/* verlet list statistics */
if(n_verlet_updates>0) verlet_reuse = n_steps/(double) n_verlet_updates;
else verlet_reuse = 0;
#ifdef NPT
if(integ_switch == INTEG_METHOD_NPT_ISO) {
nptiso.invalidate_p_vel = 0;
MPI_Bcast(&nptiso.p_inst, 1, MPI_DOUBLE, 0, comm_cart);
MPI_Bcast(&nptiso.p_diff, 1, MPI_DOUBLE, 0, comm_cart);
MPI_Bcast(&nptiso.volume, 1, MPI_DOUBLE, 0, comm_cart);
if(this_node==0) nptiso.p_inst_av /= 1.0*n_steps;
MPI_Bcast(&nptiso.p_inst_av, 1, MPI_DOUBLE, 0, comm_cart);
}
#endif
#ifdef GHMC
if(thermo_switch & THERMO_GHMC)
ghmc_close();
#endif
}
void integrate_vv(int n_steps, int reuse_forces)
{
int i;
/* Prepare the Integrator */
on_integration_start();
/* if any method vetoes (P3M not initialized), immediately bail out */
if (check_runtime_errors())
return;
/* Verlet list criterion */
skin2 = SQR(0.5 * skin);
INTEG_TRACE(fprintf(stderr,"%d: integrate_vv: integrating %d steps (recalc_forces=%d)\n",
this_node, n_steps, recalc_forces));
/* Integration Step: Preparation for first integration step:
Calculate forces f(t) as function of positions p(t) ( and velocities v(t) ) */
/* reuse_forces logic:
-1: recalculate forces unconditionally, mostly used for timing
0: recalculate forces if recalc_forces is set, meaning it is probably necessary
1: do not recalculate forces. Mostly when reading checkpoints with forces
*/
if (reuse_forces == -1 || (recalc_forces && reuse_forces != 1)) {
thermo_heat_up();
#ifdef LB
transfer_momentum = 0;
if (lattice_switch & LATTICE_LB && this_node == 0)
if (warnings) fprintf (stderr, "Warning: Recalculating forces, so the LB coupling forces are not included in the particle force the first time step. This only matters if it happens frequently during sampling.\n");
#endif
#ifdef LB_GPU
transfer_momentum_gpu = 0;
if (lattice_switch & LATTICE_LB_GPU && this_node == 0)
if (warnings) fprintf (stderr, "Warning: Recalculating forces, so the LB coupling forces are not included in the particle force the first time step. This only matters if it happens frequently during sampling.\n");
#endif
force_calc();
rescale_forces();
#ifdef ROTATION
convert_initial_torques();
#endif
thermo_cool_down();
}
#ifdef GHMC
if(thermo_switch & THERMO_GHMC)
ghmc_init();
#endif
if (check_runtime_errors())
return;
n_verlet_updates = 0;
/* Integration loop */
for(i=0;i<n_steps;i++) {
INTEG_TRACE(fprintf(stderr,"%d: STEP %d\n",this_node,i));
#ifdef BOND_CONSTRAINT
save_old_pos();
#endif
#ifdef GHMC
if(thermo_switch & THERMO_GHMC) {
if ((int) fmod(i,ghmc_nmd) == 0)
ghmc_momentum_update();
}
#endif
/* Integration Steps: Step 1 and 2 of Velocity Verlet scheme:
v(t+0.5*dt) = v(t) + 0.5*dt * f(t)
p(t + dt) = p(t) + dt * v(t+0.5*dt)
NOTE 1: Prefactors do not occur in formulas since we use
rescaled forces and velocities.
NOTE 2: Depending on the integration method Step 1 and Step 2
cannot be combined for the translation.
*/
if(integ_switch == INTEG_METHOD_NPT_ISO || nemd_method != NEMD_METHOD_OFF) {
propagate_vel(); propagate_pos(); }
else
propagate_vel_pos();
#ifdef BOND_CONSTRAINT
/**Correct those particle positions that participate in a rigid/constrained bond */
cells_update_ghosts();
correct_pos_shake();
#endif
#ifdef ELECTROSTATICS
if(coulomb.method == COULOMB_MAGGS) {
maggs_propagate_B_field(0.5*time_step);
}
#endif
#ifdef NPT
if (check_runtime_errors())
break;
#endif
/* Integration Step: Step 3 of Velocity Verlet scheme:
Calculate f(t+dt) as function of positions p(t+dt) ( and velocities v(t+0.5*dt) ) */
#ifdef LB
transfer_momentum = 1;
#endif
#ifdef LB_GPU
transfer_momentum_gpu = 1;
#endif
force_calc();
#ifdef CATALYTIC_REACTIONS
integrate_reaction();
#endif
if (check_runtime_errors())
break;
/* Integration Step: Step 4 of Velocity Verlet scheme:
v(t+dt) = v(t+0.5*dt) + 0.5*dt * f(t+dt) */
rescale_forces_propagate_vel();
#ifdef ROTATION
convert_torques_propagate_omega();
#endif
// SHAKE velocity updates
#ifdef BOND_CONSTRAINT
ghost_communicator(&cell_structure.update_ghost_pos_comm);
correct_vel_shake();
#endif
//VIRTUAL_SITES update vel
#ifdef VIRTUAL_SITES
ghost_communicator(&cell_structure.update_ghost_pos_comm);
update_mol_vel();
if (check_runtime_errors()) break;
#endif
// progagate one-step functionalities
#ifdef LB
if (lattice_switch & LATTICE_LB)
lattice_boltzmann_update();
if (check_runtime_errors())
break;
#endif
#ifdef LB_GPU
if(this_node == 0){
#ifdef ELECTROKINETICS
if (ek_initialized) {
ek_integrate();
}
else {
#endif
if (lattice_switch & LATTICE_LB_GPU)
lattice_boltzmann_update_gpu();
#ifdef ELECTROKINETICS
}
#endif
}
#endif //LB_GPU
#ifdef ELECTROSTATICS
if(coulomb.method == COULOMB_MAGGS) {
maggs_propagate_B_field(0.5*time_step);
}
#endif
#ifdef NPT
if((this_node==0) && (integ_switch == INTEG_METHOD_NPT_ISO))
nptiso.p_inst_av += nptiso.p_inst;
#endif
#ifdef GHMC
if(thermo_switch & THERMO_GHMC) {
if ((int) fmod(i,ghmc_nmd) == ghmc_nmd-1)
ghmc_mc();
}
#endif
/* Propagate time: t = t+dt */
sim_time += time_step;
}
/* verlet list statistics */
if(n_verlet_updates>0) verlet_reuse = n_steps/(double) n_verlet_updates;
else verlet_reuse = 0;
#ifdef NPT
if(integ_switch == INTEG_METHOD_NPT_ISO) {
nptiso.invalidate_p_vel = 0;
MPI_Bcast(&nptiso.p_inst, 1, MPI_DOUBLE, 0, comm_cart);
MPI_Bcast(&nptiso.p_diff, 1, MPI_DOUBLE, 0, comm_cart);
MPI_Bcast(&nptiso.volume, 1, MPI_DOUBLE, 0, comm_cart);
if(this_node==0) nptiso.p_inst_av /= 1.0*n_steps;
MPI_Bcast(&nptiso.p_inst_av, 1, MPI_DOUBLE, 0, comm_cart);
}
#endif
#ifdef GHMC
if(thermo_switch & THERMO_GHMC)
ghmc_close();
#endif
}