special v evaluation to limite dtv each time v is zeroed (022dd4a4) · Commits · 郑智淋 / lammps

src/min_fire.cpp

+38 −13

Original line number	Diff line number	Diff line
		@@ -87,6 +87,7 @@ void MinFire::setup_style()

		for (int i = 0; i < nlocal; i++)
		v[i][0] = v[i][1] = v[i][2] = 0.0;
		flagv0 = 1;
		}

		/* ----------------------------------------------------------------------
		@@ -146,18 +147,6 @@ int MinFire::iterate(int maxiter)
		v[i][2] = dtfm * f[i][2];
		}
		}
		// limit timestep so no particle moves further than dmax

		dtvone = dt;

		for (int i = 0; i < nlocal; i++) {
		vmax = MAX(fabs(v[i][0]),fabs(v[i][1]));
		vmax = MAX(vmax,fabs(v[i][2]));
		if (dtvone*vmax > dmax) dtvone = dmax/vmax;
		}

		MPI_Allreduce(&dtvone,&dtv,1,MPI_DOUBLE,MPI_MIN,world);

		}

		for (int iter = 0; iter < maxiter; iter++) {
		@@ -279,6 +268,31 @@ int MinFire::iterate(int maxiter)

		for (int i = 0; i < nlocal; i++)
		v[i][0] = v[i][1] = v[i][2] = 0.0;
		flagv0 = 1;
		}

		// 1st iter: evauates velocity
		// required to limit timestep in case of particles
		if (flagv0) {
		dtf = dt * force->ftm2v;
		energy_force(0);
		neval++;

		if (rmass) {
		for (int i = 0; i < nlocal; i++) {
		dtfm = dtf / rmass[i];
		v[i][0] = dtfm * f[i][0];
		v[i][1] = dtfm * f[i][1];
		v[i][2] = dtfm * f[i][2];
		}
		} else {
		for (int i = 0; i < nlocal; i++) {
		dtfm = dtf / mass[type[i]];
		v[i][0] = dtfm * f[i][0];
		v[i][1] = dtfm * f[i][1];
		v[i][2] = dtfm * f[i][2];
		}
		}
		}

		// limit timestep so no particle moves further than dmax
		@@ -293,6 +307,13 @@ int MinFire::iterate(int maxiter)

		MPI_Allreduce(&dtvone,&dtv,1,MPI_DOUBLE,MPI_MIN,world);

		// 1st iter: velocities reset to 0

		if (flagv0) {
		for (int i = 0; i < nlocal; i++)
		v[i][0] = v[i][1] = v[i][2] = 0.0;
		}

		// min dtv over replicas, if necessary
		// this communicator would be invalid for multiprocess replicas

		@@ -450,6 +471,10 @@ int MinFire::iterate(int maxiter)
		neval++;
		}

		// velocities have been evaluated

		flagv0 = 0;

		// energy tolerance criterion
		// only check after delaystep elapsed since velocties reset to 0
		// sync across replicas if running multi-replica minimization

src/min_fire.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -37,7 +37,7 @@ class MinFire : public Min {
		double dt,dtmax,dtmin;
		double alpha;
		bigint last_negative,ntimestep_start;
		int vdotf_negatif;
		int vdotf_negatif,flagv0;
		};

		}

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